Air and Water Temperature and Hypothermia
 

I have read somewhere that you can add up the air and water temperature
to determine the degree of hypothermia hazard. What I don't remember is
the range of total temperature that was relatively safe vs. unsafe. I
did some google searching without finding what I was looking for. I did
find some survival time tables as a function of water temperature, and
one reference that said you should wear a wet suit if either the air or
water temperature is under 65 degrees F.

I am mostly a river canoe person, but I do get out on lakes from time to
time.

Yes, I know quite a bit about hypothermia, have read a lot about it,
experienced it, pulled a hypothermic swimmer out of the water (I still
tell that story 30 years later), etc. I wear a farmer john wetsuit when
I think I might swim. I do not paddle in the wintertime.

Anybody have a pointer to an article with rules of thumb?

Richard

Hey Richard,

When I started boating the rule was water+air temp should equal 100
degrees before needing extra protective gear. Some in our club claim 120
respectfully. Another thing I consider with winter boating is adding a class
number to a normal warm weather run. Ex: I consider a Class II a calss III
in winter.
Mike
"Richard Ferguson" wrote in message
...
I have read somewhere that you can add up the air and water temperature
to determine the degree of hypothermia hazard. What I don't remember is
the range of total temperature that was relatively safe vs. unsafe. I
did some google searching without finding what I was looking for. I did
find some survival time tables as a function of water temperature, and
one reference that said you should wear a wet suit if either the air or
water temperature is under 65 degrees F.

I am mostly a river canoe person, but I do get out on lakes from time to
time.

Yes, I know quite a bit about hypothermia, have read a lot about it,
experienced it, pulled a hypothermic swimmer out of the water (I still
tell that story 30 years later), etc. I wear a farmer john wetsuit when
I think I might swim. I do not paddle in the wintertime.

Anybody have a pointer to an article with rules of thumb?

Richard

Grip wrote:
Hey Richard,

When I started boating the rule was water+air temp should equal 100
degrees before needing extra protective gear.

That's one of the most dangerous "rules of thumb" out there, as there
isn't any combination of temps equaling 100 where it's safe to not wear
immersion clothing.

Some in our club claim 120 respectfully.

This level is closer to realistic, but still not enough. Any such rule
is too much of an over-simplification to be useful or safe.

....stuff deleted

My local waters rarely reach up to the mid '50s (Fahrenheit). The
air can be 100 degrees Fahrenheit, yet the water temperature will not
change significantly. And so, I still need to be dressed in a way
that will protect me against hypothermia. The layers of insulation I
might wear over a wetsuit or under a drysuit will change according,
to some degree (no pun intended), to the air temperature, but I
always have to think about the water temperature first and foremost.

- --
Melissa


I tend to agree with Melissa and Brian. You need to dress for the water
temperature, not the air temperature. The rationale, as Melissa points
out, is that in a capsize, you will end up with your body in the water
and the air temperature won't be a factor, whatsoever. An example of
this is when we had a canoe overturn on the Sacramento just out of Red
Bluff. The two boys were hung up near snags on the side of the river. I
paddled in and extracted one on the back of my boat while the other was
hauled out with a rope by one of the other canoes (by the way, a 150LB
boy scout on the back of a sea kayak creates some interesting stability
issues, but he was already shivering and turning blue in the 45F water).

We reached shore, but even though the outside temperature was 95F+, the
area was shaded and did little to let them warm up. As we extracted the
boat and gear, I had the boys climb the bank and sit in the sun on top.
This did wonders for them in a very short time.

On the ocean, however, getting warm would have been much more difficult.
It is likely that an ocean rescue would probably have been quicker
without since there would be no shoreline hazards or current to be
concerned about (though the conditions that caused the capsize would
still exist).

Rick

Using air and/or water temperature to relate to river grades perverts the
river grading system. Dress for the water temperature on rivers. On the west
coast of Canada you can almost always see the snow that the river is coming
from. It isn't hard to figure the water temperature.

--
Sincerely,
Carey Robson -- www.CanoeBC.ca


"Grip" wrote in message
...
Hey Richard,

When I started boating the rule was water+air temp should equal 100
degrees before needing extra protective gear. Some in our club claim 120
respectfully. Another thing I consider with winter boating is adding a
class
number to a normal warm weather run. Ex: I consider a Class II a calss III
in winter.
Mike
"Richard Ferguson" wrote in
message
...
I have read somewhere that you can add up the air and water temperature
to determine the degree of hypothermia hazard. What I don't remember is
the range of total temperature that was relatively safe vs. unsafe. I
did some google searching without finding what I was looking for. I did
find some survival time tables as a function of water temperature, and
one reference that said you should wear a wet suit if either the air or
water temperature is under 65 degrees F.

I am mostly a river canoe person, but I do get out on lakes from time to
time.

Yes, I know quite a bit about hypothermia, have read a lot about it,
experienced it, pulled a hypothermic swimmer out of the water (I still
tell that story 30 years later), etc. I wear a farmer john wetsuit when
I think I might swim. I do not paddle in the wintertime.

Anybody have a pointer to an article with rules of thumb?

Richard

But what if the water temp is 75F and the air is 25F? ;-)

In that case, the biggest hazard is 6-foot visibility due to the fog...

On Fri, 21 Jan 2005 15:06:44 -0800, Melissa
wrote:

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Hi Bob P,

On Fri, 21 Jan 2005 21:16:16 GMT, you wrote:

But what if the water temp is 75F and the air is 25F? ;-)

In that case, the biggest hazard is 6-foot visibility due to the
fog...

Though not necessarily because of that type of extreme temperature
difference between water and air, I do at times find myself in that
type of visibility due to fog. It's much more reassuring in waters I
know very well though, and it definitely has its own particular
charms. A compass and the ability to navigate is always a good
thing.

I love being engulfed in fog (again, especially if it's in a
situation where I feel confident of my navigational capability in the
area), as being sensitive to sounds becomes ever more of an issue.
On my local waters, foggy paddling also provides some nice wildlife
surprises that can "pop up out of nowhere"...like whales, seals, and
the occasional sea lion, harbor porpoise, or even a shark.

Just a couple of years ago I ran into that sort of difference, but in
reverse. The air temp in Maine was in the upper 80s, while the water temp
was still in the low 40s, in June, the water hadn't warmed up, it was a
fairly cold spring up there. I didn't even get my kayak out of the van.
It would have topped 130 on the "add the temps together" scale, however.

Galen Hekhuis NpD, JFR, GWA
Guns don't kill people, religions do

Melissa wrote:


I love being engulfed in fog (again, especially if it's in a
situation where I feel confident of my navigational capability in the
area), as being sensitive to sounds becomes ever more of an issue.
On my local waters, foggy paddling also provides some nice wildlife
surprises that can "pop up out of nowhere"...like whales, seals, and
the occasional sea lion, harbor porpoise, or even a shark.

That reminds me of paddling in complete darkness not too long ago. I
found it to be a frighthening experience, especially since it was in a
long tunnel with a couple of bends and a drop in which sound bounced off
walls and where dozens of other equally "blind" boaters were paddling
somewhere near me, sometimes with much bigger and faster craft (three or
four person canoes) than my 2 metre (6'7") playboat.

--
Wilko van den Bergh wilko(a t)dse(d o t)nl
Eindhoven The Netherlands Europe
---Look at the possibilities, don't worry about the limitations.---
http://wilko.webzone.ru/

Carey Robson wrote:

Using air and/or water temperature to relate to river grades perverts the
river grading system. Dress for the water temperature on rivers. On the west
coast of Canada you can almost always see the snow that the river is coming
from. It isn't hard to figure the water temperature.

Yep, I agree. Paddling glacier melt rivers in the middle of the summer,
one learns that lesson very quickly! If I'm too hot, I'll roll to cool
off, if I'm too cold because I didn't wear enough for the water temp, I
might die.

--
Wilko van den Bergh wilko(a t)dse(d o t)nl
Eindhoven The Netherlands Europe
---Look at the possibilities, don't worry about the limitations.---
http://wilko.webzone.ru/

On Fri, 21 Jan 2005 16:11:29 -0800, Melissa
wrote:

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Hash: SHA1

Hi Wilko,

On Sat, 22 Jan 2005 00:29:36 +0100, you wrote:

That reminds me of paddling in complete darkness not too long ago. I
found it to be a frighthening experience, especially since it was
in a long tunnel with a couple of bends and a drop in which sound
bounced off walls and where dozens of other equally "blind" boaters
were paddling somewhere near me, sometimes with much bigger and
faster craft (three or four person canoes) than my 2 metre (6'7")
playboat.

Obviously, you lived to tell the tale. How are the other paddlers?
:-)

I also enjoy night paddling. Visibility is less of an issue in an
urban setting and/or if not in a long tunnel! I've paddled many times
at night in the Seattle area, and that can be a real pleasure.

Out here, there aren't many light sources other than the moon, so
most of my night paddling here is done under a full moon on clear
nights.

Here's a little something I wrote a couple years ago after waking up
in the middle of the night and going for a full moon paddle:

============================
Sings My Heart

dark purple sea
dreams in the light
of magic and moon
watersprite, awake!
it's time to dance

give me your hand
i'll take you where
gravity floats
and light sings her song
of uncharted depth

sings my heart
this silent song
sings my spirit
these waves of joy
give me your wonder
it's time to float

i recognize this
my waterborne life
this undeserved gift
this dance of tides

bring me ever home
my sea of moonlit dreaming
==============================

I used to explore caves. One of the most terrifying things I can imagine
would be to be kayaking in a cave down a rushing underground river when the
passage and river keep on going but the airspace doesn't. This, of course,
takes place in the dark, cold underground, your light having gone out long
ago. Paddling upstream I could handle, downstream is something I'd rather
avoid. In a non-overhead environment I could see how it could be quite
attractive, however.

Galen Hekhuis NpD, JFR, GWA
Guns don't kill people, religions do

On Fri, 21 Jan 2005 19:11:23 -0800, Melissa
wrote:

Being a bit claustrophobic with regards to underground exploration,
the "cave" paddling I've done is only into fairly shallow sea caves.
Do people even *paddle* in underground rivers running through caves?

A bunch of commercial caves have some sort of underground boating
experience. Bodies of water underground range from rather large lakes to
small streams. In the US, anyway. I've heard of incredible rivers and
caves, especially in the tropics. In the US most paddling in caves is
going to be accompanied by some sort of underground portage. I've been in
a few you could do some paddling in, but only a very few.

Galen Hekhuis NpD, JFR, GWA
Guns don't kill people, religions do

It isn't at all unusual for the Nantahala in NC to be foggy. The water comes
from the bottom of Nantahala Lake and is pretty cool year round. On really
hot days a thick fog can form right over the water. The first time I ever
ran it, visibility was about ten feet, as thick as I've ever seen it. I was
a definite newbie to whitewater; I can still remember how hard my heart was
beating and how dry my mouth was approaching the roar that was Quarry Rapid.
I didn't see it until I was there, let the wave turn me sideways, and I took
a swim.
I've paddled the Nanty so many times now I've lost count. I always look
forward to Quarry now, but it was absolutely terrifying that first time in
the fog.
Some examples of Nanty fog:
http://webpages.charter.net/cegen/


TB


"Galen Hekhuis" wrote in message
...
On Fri, 21 Jan 2005 15:06:44 -0800, Melissa
wrote:

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Hi Bob P,

On Fri, 21 Jan 2005 21:16:16 GMT, you wrote:

But what if the water temp is 75F and the air is 25F? ;-)

In that case, the biggest hazard is 6-foot visibility due to the
fog...

Though not necessarily because of that type of extreme temperature
difference between water and air, I do at times find myself in that
type of visibility due to fog. It's much more reassuring in waters I
know very well though, and it definitely has its own particular
charms. A compass and the ability to navigate is always a good
thing.

I love being engulfed in fog (again, especially if it's in a
situation where I feel confident of my navigational capability in the
area), as being sensitive to sounds becomes ever more of an issue.
On my local waters, foggy paddling also provides some nice wildlife
surprises that can "pop up out of nowhere"...like whales, seals, and
the occasional sea lion, harbor porpoise, or even a shark.

Just a couple of years ago I ran into that sort of difference, but in
reverse. The air temp in Maine was in the upper 80s, while the water temp
was still in the low 40s, in June, the water hadn't warmed up, it was a
fairly cold spring up there. I didn't even get my kayak out of the van.
It would have topped 130 on the "add the temps together" scale, however.

Galen Hekhuis NpD, JFR, GWA
Guns don't kill people, religions do

"TB" wrote in message
...
It isn't at all unusual for the Nantahala in NC to be foggy. The water
comes
from the bottom of Nantahala Lake and is pretty cool year round. On really
hot days a thick fog can form right over the water. The first time I ever
ran it, visibility was about ten feet, as thick as I've ever seen it. I
was
a definite newbie to whitewater; I can still remember how hard my heart
was
beating and how dry my mouth was approaching the roar that was Quarry
Rapid.
I didn't see it until I was there, let the wave turn me sideways, and I
took
a swim.
I've paddled the Nanty so many times now I've lost count. I always look
forward to Quarry now, but it was absolutely terrifying that first time in
the fog.
Some examples of Nanty fog:
http://webpages.charter.net/cegen/


A typical summer Grand Canyon run has air temps in the 110s, and wateroften
below 40. That's a 150 degree total, but the yakkers all dress for
immersion. Even in a raft, you might be sweltering so badly that your head
is reeling, but you still can't bring yourself to hop in, even for a second.

--riverman

TB wrote:
It isn't at all unusual for the Nantahala in NC to be foggy. The
water comes from the bottom of Nantahala Lake and is pretty cool year
round. On really hot days a thick fog can form right over the water.

I've beem on the Nantahala when the fog layer was hanging about 2 feet
above the water. Sit straight up and you can't see a thing; bend over
and it's crystal clear. Very disconcerting experience.

--
Steve Cramer
Athens, GA

"Galen Hekhuis" wrote in message
...
On Fri, 21 Jan 2005 19:11:23 -0800, Melissa
wrote:

Being a bit claustrophobic with regards to underground exploration,
the "cave" paddling I've done is only into fairly shallow sea caves.
Do people even *paddle* in underground rivers running through caves?

A bunch of commercial caves have some sort of underground boating
experience. Bodies of water underground range from rather large lakes to
small streams. In the US, anyway. I've heard of incredible rivers and
caves, especially in the tropics. In the US most paddling in caves is
going to be accompanied by some sort of underground portage. I've been in
a few you could do some paddling in, but only a very few.



Skocjanske Jame (jame = cave) in Solvenia
http://www.park-skocjanske-jame.si/B...keJameENG.html has a
spectacular underground river, the Reka, with torquoise-blue water and
stunning rock formations that runs through a several-miles long gorge before
emerging into a broad valley. I've always wondered what running that would
be like....I hear that it has head clearance the whole way, just a series of
underground class 2-3 rapids with pretty large falls and compression waves.

--riverman

"Wilko" wrote in message
...
Carey Robson wrote:

Using air and/or water temperature to relate to river grades perverts the
river grading system. Dress for the water temperature on rivers. On the
west
coast of Canada you can almost always see the snow that the river is
coming
from. It isn't hard to figure the water temperature.

Yep, I agree. Paddling glacier melt rivers in the middle of the summer,
one learns that lesson very quickly! If I'm too hot, I'll roll to cool
off, if I'm too cold because I didn't wear enough for the water temp, I
might die.


Hmm, I'm not so certain the I agree that considering water temps perverts
the rating system, whether or not you are dressed appropriately. Ice cold
water is harder to paddle than pleasant tropical water for many reasons
(icecream headaches from face shots, hypothermia--even with appropriate
clothing, reaction time when you flip, the strength in your hands, ice crust
and other obstacles). And dressing appropriately for icy winter water is a
pretty bulky set-up, and will effectively change how you can paddle when
compared to the same rapid on a summer t-shirt and pfd day.

Besides, its already a pretty perverted system. Its supposed to define the
difficulty of the rapids, but what determines that? A rocky rapid is
harder in a breakable glass boat than in a plastic one. A beginner will find
the same rapid impossible that an expert finds simple. A raft and a kayak
will seldom agree on the difficulty of a rapid. A remote rapid with little
chance for rescue is considered harder than the exact same rapid if a road
was put in right next to it. A certain rapid is much harder in a torrential
rain with poor visibilty, or a snowstorm than on a sunny summer day. The
list goes on, and most folks have a very informal allegiance to it anyway.

Unless we want to standardize *everything*, rating systems regularly take
all sorts of variables into account, and produce all sorts of variations. To
truly have a standard system, I imagine a system that is based on assuming
all paddlers on all rivers:
a) wear appropriate clothing for whatever the current weather is and
that the particular clothing does not affect their paddling on that day.
b) are in the same type of boat ('glass, plastic, rubber, whatever)
which are the same type (raft, yak, canoe) and the same style (squirt,
downriver, playboats, slalom....)
d) have the same theoretical access/egress availability and accessiblity
for rescue
e) are being paddled by the same type of paddler (beginner,
intermediate, expert...)

etc etc.
As long as grading systems are NOT standardized for the myriad of possible
variables, then there's nothing perverse about including the restrictions of
clothing as a factor, IMHO.

--riverman

TB wrote:

It isn't at all unusual for the Nantahala in NC to be foggy. The water comes
from the bottom of Nantahala Lake and is pretty cool year round. On really
hot days a thick fog can form right over the water. The first time I ever
ran it, visibility was about ten feet, as thick as I've ever seen it.

I know! I HATE that! I've run the Nanty namy times, and occasionally, at least
once I remember, it was so foggy I could not see most eddies until it was too
late to set up to catch them! And eddies and eddy practice is superb on the
Nanty, but only when you can see 'em and catch 'em, yano? ;-)

John Kuthe...

John Kuthe wrote:
I know! I HATE that! I've run the Nanty namy times, and occasionally, at least
once I remember, it was so foggy I could not see most eddies until it was too
late to set up to catch them! And eddies and eddy practice is superb on the
Nanty, but only when you can see 'em and catch 'em, yano? ;-)

The Force, John, use the Force! Don't look for the eddies, listen for them.

--
Steve Cramer
Athens, GA

Steve Cramer wrote:

John Kuthe wrote:
I know! I HATE that! I've run the Nanty namy times, and occasionally, at least
once I remember, it was so foggy I could not see most eddies until it was too
late to set up to catch them! And eddies and eddy practice is superb on the
Nanty, but only when you can see 'em and catch 'em, yano? ;-)

The Force, John, use the Force! Don't look for the eddies, listen for them.

--
Steve Cramer
Athens, GA

I'm far too visually dependent!! ;-) Besides, many eddied sound just like a ROCK,
yano? Hee hee!

John Kuthe...

riverman wrote:
"Wilko" wrote in message
...

Carey Robson wrote:


Using air and/or water temperature to relate to river grades perverts the
river grading system. Dress for the water temperature on rivers. On the
west
coast of Canada you can almost always see the snow that the river is
coming
from. It isn't hard to figure the water temperature.

Yep, I agree. Paddling glacier melt rivers in the middle of the summer,
one learns that lesson very quickly! If I'm too hot, I'll roll to cool
off, if I'm too cold because I didn't wear enough for the water temp, I
might die.



Hmm, I'm not so certain the I agree that considering water temps perverts
the rating system, whether or not you are dressed appropriately.

I agreed with the dressing for the water temp, that's all.

I guess I should have clipped the first sentence of Carey wrote.

--
Wilko van den Bergh wilko(a t)dse(d o t)nl
Eindhoven The Netherlands Europe
---Look at the possibilities, don't worry about the limitations.---
http://wilko.webzone.ru/

If you are dressed for the water temp, are you automatically dressed
for the air temp?

People die up here in Colorado every year from hypothermia, without
ever getting in the water. All they need to do is get a little wet from
rain or even sweat, and at 50F they can become hypothermic. Wind chill
is important and especially if you are wet, and setting still in a
kayak, unable to exercise enough to stay warm. Combine that with the
possibility of having become tired, hungry, and seriously chilled if
you did take a swim, recovery air temp could be real important! TnT

[snippage]
I don't really bother to
think in terms of a standardized rating system. I may not quantify
conditions "by the numbers", but I guess somewhere inside me there's
my own mysterious and particular (peculiar?) rating system. :-)

- --
Melissa

Being a relatively new paddler (about 3 years and can't get out enough). I
also have developed my own peculiar rating system.

1- Oh how boring, but maybe the view will make up for it.
2 - This looks promising.
3 - I think I can
4 - See you folks later for dinner, cause there ain't no way I'm goin out
today.

So far it has worked. I only had to invoke number 4 once last year on a trip
to Lake Erie. They were breaking 4-6 footers and I'm not ready yet. It would
have been a launch from rocks on top of that. I was the first to say no and
quickly everyone decided that the river was a better bet for the day. We did
the Vermillion river that day and ended up doing one of the protected bays
the next. We paddled out and took a look at the lake but I'm not even sure
we could have pushed out past the breakwater. We did have 2 people that went
out past the breakwater from the Vermillion river the first day. They were
doing pretty good and then one of them went for a swim and in the process of
3-4 reentries his paddle broke. While they did have a spare on the rear deck
of one of the boats they made the decision to tow the capsized boater into
shore. They landed on a private beach quite to the amusement of the
homeowner. He offered a ride to one of the guys and they came and got the
rest of the group to bring the kayak trailer around to collect the boats and
the swimmer. Gave us something to talk about during dinner.


Ken

"No Spam" wrote in message
news:Vb_Id.14464$1l2.1670@trndny05...
[snippage]
I don't really bother to
think in terms of a standardized rating system. I may not quantify
conditions "by the numbers", but I guess somewhere inside me there's
my own mysterious and particular (peculiar?) rating system. :-)

- --
Melissa

Being a relatively new paddler (about 3 years and can't get out enough). I
also have developed my own peculiar rating system.

1- Oh how boring, but maybe the view will make up for it.
2 - This looks promising.
3 - I think I can
4 - See you folks later for dinner, cause there ain't no way I'm goin out
today.

So far it has worked. I only had to invoke number 4 once last year on a
trip
to Lake Erie. They were breaking 4-6 footers and I'm not ready yet. It
would
have been a launch from rocks on top of that. I was the first to say no
and
quickly everyone decided that the river was a better bet for the day. We
did
the Vermillion river that day and ended up doing one of the protected bays
the next. We paddled out and took a look at the lake but I'm not even sure
we could have pushed out past the breakwater. We did have 2 people that
went
out past the breakwater from the Vermillion river the first day. They were
doing pretty good and then one of them went for a swim and in the process
of
3-4 reentries his paddle broke. While they did have a spare on the rear
deck
of one of the boats they made the decision to tow the capsized boater into
shore. They landed on a private beach quite to the amusement of the
homeowner. He offered a ride to one of the guys and they came and got the
rest of the group to bring the kayak trailer around to collect the boats
and
the swimmer. Gave us something to talk about during dinner.

Both you, Ken, and Melissa bring up a very good point. Ocean and lakes are
NOT rated by the traditional river rating system, because the conditions are
so variable. As a result, folks who play on the beach are welcome to devise
their own rating system, and it is inevitably based on their own ability
to run that particular water. And on any particular day, three different
boaters may rate the same beach waves differently, depending on their skills
and equipment.

River runners need a similar system, or else there will be the same old
arguments forever about whether or not class 4 is 'runnable' in an open
boat, or class 5 is 'runnable' at all.....

--riverman

riverman wrote:


Nonetheless, we can morph this into a rating system thread, if you want. :-)

Sure, why not, RBP seems to have come alive again, and I enjoy the
direction that some of these discussions are going. :-)

What do you think: two identically skilled paddlers in the same type boat,
on the same day, paddling the same river together. One is dressed
appropriately, one is underdressed significantly. Is the river rated the
same?

Not according to me. I rate the difficulty of a rapid by how difficult
it is to stay on the line, i.e. the skill necessary to stay on that
particular line through that rapid.

Danger or risk is not part of the rating for me, but it does have a big
impact on whether or not I would run something, despite the rating.

I was thinking about this on the way home, and began to get a grip on the
problem with the rating system...allow me to soapbox a bit.

:-)

The solution is simple. The first step has to be to clearly and
unambiguously define as much about that 'imaginary person' as possible. What
boat, what clothing, what skills, etc. And that imaginary person has to be
standard for all rivers, everywhere. Of course, we can always invoke the
'reasonable man test', as they do in law. "A reasonable person in such a
situation", but I don't think the disparate types of boaters could ever come
to agreement on what a standardized 'reasonable man' is. But until it is
clearly defined, any attempt to make a river rating system is doomed to
failure.

Hmmm, so what according to you does the clothing of said imaginary
boater have to do with how difficult it is for him to stay on his line?

Anyway, my proposal: some recognized authoritative body must clearly define
who the 'Reasonable Boater' is: what skills, what boat, what gear, as well
as what the environmental situation is: what temp (air and water), what
river level, what sky conditions are, etc. Then, all rating systems
worldwide would be correlated and usable. If a person was in a more stable
boat than the Reasonable Boater Standard, they could modify *all* river
rating worldwide by just adjusting the rating system on their local river
accordingly. Sort of their personal handicap.

Sounds a bit like (in part) what AW has tried to do...

In this way, a river's actual rating is meaningless. There is NO 'class 4
rapid', because no one is really the Reasonable Boater. But what is class 4
for YOU may be class 3 for someone who is a much stronger paddler, and
class 5 for a newbie. Which actually represents reality much more, since
people will argue all day about whether a class 4 rapid is runnable.

I think that most difficulty ratings have grey areas, but for me the
clearest line was the one between class III and class IV. Suddenly I
found myself acutely aware of the differences between the two, it just
felt so clearly different. Now that I've run plenty of each, I find that
they seem to get closer, but still I find them to be rather clearly
distinquishable. Do we need a clearer distinction? Maybe... For me it's
more an indicator that is joined by a number of equally subjective
arguments and measurements like tiredness, confidence, risk, danger,
distance from the nearest help and so on.

Wilko

--
Wilko van den Bergh wilko(a t)dse(d o t)nl
Eindhoven The Netherlands Europe
---Look at the possibilities, don't worry about the limitations.---
http://wilko.webzone.ru/

....stuff deleted

Both you, Ken, and Melissa bring up a very good point. Ocean and lakes are
NOT rated by the traditional river rating system, because the conditions are
so variable. As a result, folks who play on the beach are welcome to devise
their own rating system, and it is inevitably based on their own ability
to run that particular water. And on any particular day, three different
boaters may rate the same beach waves differently, depending on their skills
and equipment.

River runners need a similar system, or else there will be the same old
arguments forever about whether or not class 4 is 'runnable' in an open
boat, or class 5 is 'runnable' at all.....


Valid points, all. After reviewing the Tsunami Ranger's rating system, I
was fairly impressed by the number factors they consider, but as was
pointed out, common sense (gee, this looks dangerous) is the best
defense. Too many seem to lack the skill and are overly optimistic about
the conditions.

In my ocean trips, I always ask others for an assessment of the
conditions. Often, I stay out of it, entirely, until everyone has their
say. If anyone feels uncomfortable with the conditions, we change the
paddling plan (calmer sites are often available). Sometimes, I make the
choice for the group to change the plan (if I am leading, that is).
There are times when novices choose conditions that are beyond their
skill and I've seen this both in paddling and diving.

Sadly, nobody is completely innocent of this. Sometimes, having a mix of
novices and experienced paddlers is what keeps a group from making the
wrong choices.

Rick

"Melissa" wrote in message
...
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Hi Rick,

On Tue, 25 Jan 2005 03:41:01 GMT, you wrote:

Sometimes, having a mix of novices and experienced paddlers is what
keeps a group from making the wrong choices.

I solve this problem by paddling solo most of the time! Well, almost,
as I can still have some pretty entertaining discussions with myself
before deciding to do something stupid; then I go ahead and do
something stupid, because after all, sometimes the "stupid me" is the
designated leader of the trip! :-)

Seriously though... (my comments to follow are related specifically to
sea kayaking, as my experience with whitewater river paddling is very
limited to date; though I intend to do more of it!).

All the variables that the Tsunami Rangers consider are valid, and
good to think about; whether paddling with a group or paddling solo.
I still don't use the rating system as such, because I just don't
want to spend half an hour sitting on the beach playing with a
calculator before I go paddling!

Also, while the Ranger's system does consider various potentialities
"in general", it necessarily disregards several specific
possibilities that can be unique in every different place, like
shoals, very specific configurations of rock gardens and sea caves,
and how these influence conditions in those areas during various
times of the tide/current cycles, and in various weather conditions.
No matter how specific we can get with the numbers at the time of
launching, we have to constantly reevaluate conditions while on the
water based on our overall situational awareness.

Even as I begin to write this, I'm realizing that I can just keep on
writing without end, trying not to forget some important detail here
and there, yet in reality, all these things are also "considered" in
a transparent way that is as natural as breathing, and what might
take five single spaced pages to *try* and explain actually flashes
by in an instant of simply "being in the moment" while standing on
shore or paddling on the water.



If I'm reading you correctly, Melissa, you bring up an incredibly salient
point, which is: "What is a rating system used for?"

When I was leading canoe trips in the NWT, I would often come across a rapid
and have to decide whether or not to run it, to let the clients run it, or
to line it. I never rated the rapid, or even cared an iota what it was
rated....my decision was not based on the rating; it was based on being 'in
the moment', looking at the rapid and making an educated judgement.

Rating systems are actually not for making on-site decisions. They are for
communciating things to people who are not there.

For example, someone deciding if they are going to run a certain long rapid
might ask someone what it does around the corner. Being 'half' in the
moment, the other person might say "Oh, it continues like this part
here....no larger than an easy class 3." At least that person has a
reference for what the other person is describing.

Or I might have to explain why I did not let the clients run a certain drop.
I would tell my boss "it was a tricky class 3, they weren't up to it".

Then you might have someone who is packing for a trip on a river they have
never done before. The guidebooks all agree that this river has certain
Class 4 rapids, so the tripper has to use that information to decide what
kind of gear to bring, how long the trip will be, what boat to paddle. Thats
where internally consistent grading systems become important: for the folks
who cannot just be 'in the moment' and need some info about the river to
prepare for it. And this is where the system sometimes breaks down. I
remember when I ran the MidFork Salmon at flood stage: there were boaters
from both coasts on the trip, in kayaks and rafts, and the first 20 miles
was rated 'Class 3'. We all were shocked at how technical, continuous and
irregular the wave were, and all the East Coast boaters insisted that this
was class 4. The west coast boaters (who were used to Grand Canyon sized
rapids) insisted that these were really more like an easy class 3. We ended
up compromising and calling them "Idaho Class 3s". But forever after that,
whenever I was running a Western river that was rated Class 3 or 4, I had no
idea if I could get down it in an open boat, although I had been running
Class 4 rapids in my open boat in the East Coast for years.

I'm pretty sure that this is because most NorthEastern rivers (and North
Central) are rated from the perspective of a canoeist, since the history of
that region is the history of the Voyageurs. However, SouthEastern rivers
are rated from the perspective of kayakers, being the home of recreations
steep-creeking. And Western Rivers are rated from the perspective of
Oarsmen, thanks to the Post WW2 army surplus pontoons . For each of these
boaters, the same river would pose different obstacles and have differing
difficulties. As an open boater, I could not possibly distinguish between
Class 4+, Class 5- and Class 5+. As a rafter (or a solid kayaker), Class 2-,
2+ and 3- are pretty indistingiushable (and boring). As a result, there is
some internal inconsistency between regions.

The hardest part comes when we are trying to correlate rapids of very
different nature in different places. A class 3 in Maine on a rocky,
clearwater woods stream like the Penobscot will be different than a Class 3
in the Grand Canyon (if you adjust the Canyon scale accordingly), and will
be different than a Class 3 on the Orange in South Africa, which is a desert
river. Different types of rock, different volumes of water, different shaped
waves all change the charteristics of the rapids so that, as per Oci-One's
assertation: class 3s are harder than class 2s, but the problem is that not
all Class 3s are equally hard.

Funny thing, however, is when some people let the rating system override
their momentary presence. These are folks who get laundered in some rapid,
then amazingly declare "Hey, I should have been able to run that! The book
says its only class 3!"...even though their eyes told them at the scout rock
that it would have probably been rated a class 4 if it had been back in
their home state.

--riverman

I too noticed that the biggest change I found was between class III and
class IV. Another big change I noticed was when I moved from the east coast
to the west coast. I had done a few big water runs in the east but they
seemed nothing like the one's in the west. To me, generally speaking, west
coast big water class III feels like a class IV; whereas their technical,
lower volume class IV feels like a class III. I've noticed in some of the
western whitewater books they make mention if the river is a big water run
which is exactly what I like to know. It would be nice if that could be a
staple in all whitewater books.

Courtney


I think that most difficulty ratings have grey areas, but for me the
clearest line was the one between class III and class IV. Suddenly I
found myself acutely aware of the differences between the two, it just
felt so clearly different. Now that I've run plenty of each, I find that
they seem to get closer, but still I find them to be rather clearly
distinquishable. Do we need a clearer distinction? Maybe... For me it's
more an indicator that is joined by a number of equally subjective
arguments and measurements like tiredness, confidence, risk, danger,
distance from the nearest help and so on.

Wilko

--
Wilko van den Bergh wilko(a t)dse(d o t)nl
Eindhoven The Netherlands Europe
---Look at the possibilities, don't worry about the limitations.---
http://wilko.webzone.ru/

"Courtney" wrote in message
ink.net...
I too noticed that the biggest change I found was between class III and
class IV. Another big change I noticed was when I moved from the east
coast
to the west coast. I had done a few big water runs in the east but they
seemed nothing like the one's in the west. To me, generally speaking,
west
coast big water class III feels like a class IV; whereas their technical,
lower volume class IV feels like a class III. I've noticed in some of the
western whitewater books they make mention if the river is a big water run
which is exactly what I like to know. It would be nice if that could be a
staple in all whitewater books.



Yes, your perceptions are right on, Courtney. The lines get blurry at the
edges.

The reason for disparity at the Class III, Class IV boundary is that class
I,II and III rapids are primarily rated by canoeists, as that's their
'specialty water' and they can really split hairs. Class III+ is up near the
top end, and to an open boater, looks awful similar to Class IV-.

Likewise, class IV and V water is primarily rated by yakkers, as that is
their specialty water, and to them, class III looks suspiciously similar
to easy class IV.

As a result, there are a LOT of rapids rated class 3+ or 4- which have very
little similarity, except that they are really challenging for an open boat
and a bit easy for a kayak.

Similarly, eastern water is rated by yakkers and canoeists, but western
water is rated by rafters. Eastern boaters wouldn't automatically add a few
levels just because there are rocks in a rapid, but western boaters
(especially big water boaters) freak out at rocks. Look at Hance in the GC:
no way thats a 10, but tell that to those rubber boaters who are used to
punching 10 foot waves. Similarly, try to convince an east coast boater
that, just because there's a 10 foot wave in a rapid, its not necessarily a
class V.

In fact, when I travelled around the NW around 1985 or so, and was running
(eastern-style class 3) water in my BlueHole 17A, I was what most easterners
considered a dinosaur and an advanced-intermediate boater, but on most of
the western rivers I ran, no one had ever seen a canoeist before, and I was
cutting edge. Rather funny at the time. :-)

--riverman

Melissa wrote:
-----BEGIN PGP SIGNED MESSAGE-----
....stuff deleted

All the variables that the Tsunami Rangers consider are valid, and
good to think about; whether paddling with a group or paddling solo.
I still don't use the rating system as such, because I just don't
want to spend half an hour sitting on the beach playing with a
calculator before I go paddling!


Melissa,

I've watched Eric and co. paddling on the Monterey Coast. They spend
only a few seconds making their assessments, but then, there is little
these guys are not capable of handling (if there is, they are in
conditions few others would consider paddling, must less bother rating).
As with any system, it needs to be adapted to consider the prevailing
conditions. According to what I've read, they rate the trip before
leaving based upon their expectations of the conditions. When they
arrive, they judge the conditions and determine whether the trip needs
to be re-rated. When they arrive, unless conditions are considerably
different than their expectations, they pretty much just put the boats
in the water and go.

Also, while the Ranger's system does consider various potentialities
"in general", it necessarily disregards several specific
possibilities that can be unique in every different place, like
shoals, very specific configurations of rock gardens and sea caves,
and how these influence conditions in those areas during various
times of the tide/current cycles, and in various weather conditions.
No matter how specific we can get with the numbers at the time of
launching, we have to constantly reevaluate conditions while on the
water based on our overall situational awareness.


Again, they tend to paddle in familiar areas. Like our WW bretheren, who
seem to paddle the same rivers over and over (probably because there
aren't that many wild rivers left), the rangers have their own favorite
coastal spots in the Monterey/SF Bay areas. When paddling south of
Monterey, where landing sites are few, conditions are consistently
rough, rocks are plentiful, etc. they are paddling in areas they have
already rated. I'm sure they've been surprised, however, nonetheless.

....stuff deleted

================================================== ===================
Don't underestimate conditions to be macho or sucker people into doing
activities beyond their skill. The SCRS is useful but artificial; it
only estimates, not guarantees the actual risks you will face.
Finally, keep in mind that the SCRS is at best a general guideline,
an indicator; it doesn't account for freak incidents such as
williwaws or rogue waves. Its main value is it encourages kayakers to
take the time and effort needed to assess the complex factors which
comprise the sea.
================================================== ===================


I left this in because it bears repeating.

I paddled on the sea for a long time before I even heard about the
Tsunami Ranger's rating system, so reviewing it "after the fact" is
interesting, but I still see no particular need to play a numbers
game every time I want to go paddling. Once we've been paddling a
while, in addition to knowing something about tides and currents,
wave dynamics, shoals and other underwater features, shoreline
topography, weather, and what's possible on truly open water (not
just near shore), we can develop a "feel" for the overall conditions,
and what to expect in terms of changes as the day progresses. As we
can see by how detailed the Ranger's rating system is, we can also
see how someone not so well versed in "sensing" the conditions for
themselves can kind of trip over all the numbers, and become even
more confused than ever by trying to quantify too precisely the fluid
conditions (no pun intended) with numbers, because those conditions
are always changing, and sometimes, they can change very suddenly and
severely indeed.


I first came upon the rangers when I started paddling many (about 15)
years ago. Back then, they were already on their way to building this
system. Though its been around for a while, I haven't used it myself.
Mostly, like you, I use the "god, this looks stupid," rule-of-thumb.

Being too concerned with constantly recalculating the *numbers* is
sort of like trying to constantly evaluate and compensate for all the
particular muscle movements required as we walk. If we do this,
we'll either take a year to walk a short distance, or we'll simply
fall down.



And I just thought I was slow.

Rick

You're right about many western boaters freaking out about rocks.
Personally I love them. They make the rapids fun and full of possibilities!

I don't know anything about class III and less generally rated by canoeist
and IV and V by kayakers. I haven't really paid that much attention to what
paddlers are rating what. I personally find that in a canoe or a kayak the
rapids seem about the same to me. In fact strangely enough, I find paddling
some class IV's in my canoe easier than in my kayak. Yet I've paddled V's
in my kayak but would never take my canoe on one. Don't ask me why because
really I don't know why. I know everyone is different but I can't see why
there would be a real difference between kayakers and canoeists and their
ratings? As I mentioned I personally find them to feel basically equal. I
can understand that I see more kayakers on class IV / V. Maybe that's it.
Can you expand on how you came to that?

Courtney

"riverman" wrote in message
...

"Courtney" wrote in message
ink.net...
I too noticed that the biggest change I found was between class III and
class IV. Another big change I noticed was when I moved from the east
coast
to the west coast. I had done a few big water runs in the east but they
seemed nothing like the one's in the west. To me, generally speaking,
west
coast big water class III feels like a class IV; whereas their
technical,
lower volume class IV feels like a class III. I've noticed in some of
the
western whitewater books they make mention if the river is a big water
run
which is exactly what I like to know. It would be nice if that could be
a
staple in all whitewater books.



Yes, your perceptions are right on, Courtney. The lines get blurry at the
edges.

The reason for disparity at the Class III, Class IV boundary is that class

I,II and III rapids are primarily rated by canoeists, as that's their
'specialty water' and they can really split hairs. Class III+ is up near
the
top end, and to an open boater, looks awful similar to Class IV-.

Likewise, class IV and V water is primarily rated by yakkers, as that is
their specialty water, and to them, class III looks suspiciously similar
to easy class IV.

As a result, there are a LOT of rapids rated class 3+ or 4- which have
very
little similarity, except that they are really challenging for an open
boat
and a bit easy for a kayak.

Similarly, eastern water is rated by yakkers and canoeists, but western
water is rated by rafters. Eastern boaters wouldn't automatically add a
few
levels just because there are rocks in a rapid, but western boaters
(especially big water boaters) freak out at rocks. Look at Hance in the
GC:
no way thats a 10, but tell that to those rubber boaters who are used to
punching 10 foot waves. Similarly, try to convince an east coast boater
that, just because there's a 10 foot wave in a rapid, its not necessarily
a
class V.

In fact, when I travelled around the NW around 1985 or so, and was running
(eastern-style class 3) water in my BlueHole 17A, I was what most
easterners
considered a dinosaur and an advanced-intermediate boater, but on most of
the western rivers I ran, no one had ever seen a canoeist before, and I
was
cutting edge. Rather funny at the time. :-)

--riverman

"Courtney" wrote in message
ink.net...
You're right about many western boaters freaking out about rocks.
Personally I love them. They make the rapids fun and full of
possibilities!

I don't know anything about class III and less generally rated by canoeist
and IV and V by kayakers. I haven't really paid that much attention to
what
paddlers are rating what. I personally find that in a canoe or a kayak
the
rapids seem about the same to me. In fact strangely enough, I find
paddling
some class IV's in my canoe easier than in my kayak. Yet I've paddled V's
in my kayak but would never take my canoe on one. Don't ask me why
because
really I don't know why. I know everyone is different but I can't see why
there would be a real difference between kayakers and canoeists and their
ratings? As I mentioned I personally find them to feel basically equal.
I
can understand that I see more kayakers on class IV / V. Maybe that's it.
Can you expand on how you came to that?

Courtney

Sure, let me try to explain.

Read the rating scale; who is it written for? If it were truly just a
quantitative descriptive scale which allowed boaters to make their own
assessments about whether or not a rapid could be run, then why does it
contain such qualifiers as 'easy', 'moderate', 'advanced'? Those descriptors
are accurate only from the eye of a kayaker: class 1 really IS 'easy', class
2 really is 'novice', class 4 IS 'advanced', class 5 IS 'expert'. But to a
traditional open canoe, no floatation, no saddle, those descriptors are
skewed, especially at the upper end. Class 1 is novice, class 2+/3- is
'advanced', class 3+/4- is 'expert', class 5 is suicidal. Its NOT an
'intermediate' canoeist who is running large class 3 rapids. Intermediate
canoeists are the folks who lead summer camp. :-)

(Let me add, also, that this is not an inappropriate or immature type of
canoe. Tripping or recreational canoes are traditionally one of the most
common inland vessels on rivers, especially in the east. When a canoe is
given rocker, floatation, a saddle and thigh straps, gear is lashed in,
etc...it becomes a new thing. A canoe-kayak hybrid. As such (being more
similar to a kayak than a tripping canoe), the rating scale will naturally
tend to fit better. But remember; the scale is allegedly NOT supposed to be
taking different types of boats into consideration...)

But canoeists are the ones who spend their lives on the smaller rapids. Yes,
they probably do feel quite similar in a canoe or a kayak, but the
difference is that an open general-purpose boat is at the upper sweet spot
of its intended use range in class 2, while a kayak is way at the bottom.
Canoeists will be able to clearly differentiate between a class 2- and 2+
river, because those differences will affect their boat greatly. A kayak,
however, will not be much affected by the differences, and will not be so
good at differentiating the ratings. Thus, Class 1-3 rapids are pretty much
defined by how they affect canoes, class 3-5 by how they affect kayaks.

--riverman

riverman, what are the odds of disaster? Is that what we are trying to
figure out? How far can we go to the edge of the safety net, and not
fall out. For each of us the safety net is at a different point, all
things considered!

I came across this interesting article that I think might apply:

The Odds of Disaster -
http://tinyurl.com/646ot

One way of analysing the - go/no go - scenario, is to consider
threshold factor. Such as threshold temps when hazardous results are
certain. Can you as an experienced kayaker, define those thresholds for
those of us who don't have the experience.

Brian Nystroms experience recently of the gasp reflex at 50F would
indicate a higher risk before cold water hypothermia would occur. What
are the specific risks, and what are the thresholds. A swim in a class
IV tropical river may be that after a long swim, you get chewed on by
pirrana, or crocadile, but the actual swim wasn't so bad.

We still may go, but we will have a better idea what to expect.

What is beyond a blind turn none of us can ascertain, but that is the
thrill of life! TnT

"Tinkerntom" wrote in message
ups.com...
riverman, what are the odds of disaster? Is that what we are trying to
figure out? How far can we go to the edge of the safety net, and not
fall out. For each of us the safety net is at a different point, all
things considered!

I came across this interesting article that I think might apply:

The Odds of Disaster -
http://tinyurl.com/646ot

That IS an interesting article; I suggest everyone read it! Good find, tom.

The summary is both important and counterintuitive:
Providing such things as insurance cause people to assume higher risks; a
process called "moral hazard". Drivers drive worse because they are covered.
People take health risks because they are covered. The climbers in the story
took out insurance on their climb, because a certain baseline of protection
is wise, but similarly they knew that too much protection causes moral
hazard, so they chose NOT to carry their satellite phone on the climb, as it
would have made them take more risks, thinking rescue was only a phone call
away.

To me, that underscores the importance of recognizing the essential, but
minimal safety precautions we should take. Too much protection = too much
moral hazard (as a raft guide, we knew about this 20 years ago, when we
decided NOT to give our clients helmets. We called it the 'gladiator
syndrome': give them helmets and they feel invincible and inevitably get
hurt more often than if they feel a bit vulnerable.)


One way of analysing the - go/no go - scenario, is to consider
threshold factor. Such as threshold temps when hazardous results are
certain. Can you as an experienced kayaker, define those thresholds for
those of us who don't have the experience.

I'm a canoeist, not a kayaker, but your question is well-taken. The response
is; if not me, then who? As a beginner kayaker, are YOU qualified to define
those thresholds? I think not...which is why we have such things as
protocols (minimal acceptable gear, safety procedures, etc). Which is also
why it is so crucial that things like the Rating Scale are well-understood,
accurate, and provide enough info to be useful.

Not sure where this post and reply are coming from (you didn't include any
hint as to what post you were responding to), but this is really interesting
anyway.

--riverman

On 26-Jan-2005, "riverman" wrote:

Providing such things as insurance cause people to assume higher risks; a
process called "moral hazard".

Also called "risk homeostasis". When something is used or changed to
decrease risk, people tend to increase the risk to its original level
by changing something else. Unfortunately, since people are _extremely_
poor at assessing risk, their attempts to maintain a level of risk
often turn into increased risk. Perfect example - all the four-wheel-
drive SUVs in the ditches along the roads in winter here in the Great
White North.

Risk homeostasis has been discussed a lot in the context of kayaking
on the Paddlewise mailing list. It's a big problem unless the paddler
is aware of it and compensates.

Mike

PS - I've also heard it called "Volvo Syndrome" - put someone in a
safer car and they drive like idiots.

Richard Ferguson wrote:
I have read somewhere that you can add up the air and water
temperature
to determine the degree of hypothermia hazard. What I don't remember
is
the range of total temperature that was relatively safe vs. unsafe.
I
did some google searching without finding what I was looking for. I
did
find some survival time tables as a function of water temperature,
and
one reference that said you should wear a wet suit if either the air
or
water temperature is under 65 degrees F.

I don't see where air temperature is really a factor for this, since it
can have a high variability and only some relation to water
temperature. You can check out some sites on Web sites at sites or
gages with air and water temperature. The two are related at times for
natural streams, especially at the extremes, for very cold and very
warm periods. But where the water temperature is effected by other
factor, glacier runoff, rain, snowmelt, and the ever-present dam
releases, the two aren't well related.

Some examples in Washington State a

http://waterdata.usgs.gov/wa/nwis/uv..._no= 12056500
http://waterdata.usgs.gov/wa/nwis/uv...te_no=12058800

The first is above a reservoir, the second below, at slightly different
elevations but not significantly for many cold days.

Interesting thought, but questionable application.

--Scott--

Scott M. Knowles "Opinions expressed are entirely my own."

Hydrologist, MS-Geography

"All things merge into one, and a river runs through it."
- Norman MacLean

"wsrphoto" wrote in message
oups.com...
Richard Ferguson wrote:
I have read somewhere that you can add up the air and water
temperature
to determine the degree of hypothermia hazard. What I don't remember
is
the range of total temperature that was relatively safe vs. unsafe.
I
did some google searching without finding what I was looking for. I
did
find some survival time tables as a function of water temperature,
and
one reference that said you should wear a wet suit if either the air
or
water temperature is under 65 degrees F.

I don't see where air temperature is really a factor for this, since it
can have a high variability and only some relation to water
temperature. You can check out some sites on Web sites at sites or
gages with air and water temperature. The two are related at times for
natural streams, especially at the extremes, for very cold and very
warm periods. But where the water temperature is effected by other
factor, glacier runoff, rain, snowmelt, and the ever-present dam
releases, the two aren't well related.

Some examples in Washington State a

http://waterdata.usgs.gov/wa/nwis/uv..._no= 12056500
http://waterdata.usgs.gov/wa/nwis/uv...te_no=12058800

The first is above a reservoir, the second below, at slightly different
elevations but not significantly for many cold days.

Interesting thought, but questionable application.

--Scott--


Hee hee. I hate when I do that.

--riverman
(PS: its not HOW the air temp affects the water temp that matters. Its how
the air and water temp affect YOU.)