Lawrence James wrote:
http://www.naval.com/heavy-seas/3/

If you examine the first picture and the next to the last picture showing
the huge wave on this page very closely you will figure out that the next to
the last picture is a hoax. Look closely at the details of the boat in the
first picture and closely at those identical details on the next to the last
one. Look at the water detail around the rear of the boat, identical. The
hoax picture appears on one of the other pages too.

This one has been argued in numerous NG's. The general feeling is that
you are correct.

So what is the consensus on measuring a wave. Do you measure from the
average water height to the top of the wave? Or from the bottom of the
preceeding trough to the top of the wave?

Bottom of trough to top.

A 60 ft high ship can easily have a 30 foot wave break over it if the back
of the ship is still on top of the prior wave and the nose is in the trough.

A good number of ships, exceed the wave length, and don't forget, they
are "driving" through, so, it's not all that uncommon between the
pitching and driving force, to take a wave over, but basically, you are
correct.

otn

Taking a sea, backwards, over the stern is one of those rare
occurrences that need to be seen to be believed.
We learned our lessons well that trip and instituted a number of heavy
weather no-no's.

otn

Rick wrote:
otnmbrd wrote:

G I've got another one about being on the stern and taking a sea
backwards, over the stern ....


That is what led to the practice of "securing the deck" and locking
ourselves inside. Ernie K. Gann's son was lost on that run when they
took a sea over the stern while trying to secure some barrels that were
adrift.

Sometimes we would take a gander out the door leading from the ER to the
stern on the main deck when we were closed up ... the sight of those
waves so far overhead is definitely a spiritual experience!

Rick

On Tue, 16 Mar 2004 20:12:33 GMT, Rick
wrote:

otnmbrd wrote:
G I've got another one about being on the stern and taking a sea
backwards, over the stern ....

That is what led to the practice of "securing the deck" and locking
ourselves inside. Ernie K. Gann's son was lost on that run when they
took a sea over the stern while trying to secure some barrels that were
adrift.

Sometimes we would take a gander out the door leading from the ER to the
stern on the main deck when we were closed up ... the sight of those
waves so far overhead is definitely a spiritual experience!

Ok, I have a sort-of "sea" story.

Back when I was a fresh out of school graduate engineer, I was asked
to help troubleshoot a radar installation for one of our customers.
It was on the David P. Guidry which was a deep sea oil rig service
boat - big boat.

As it happened, the Guidry was at the Lykes Shipyard across the river
from New Orleans for it's initial trials - that's where I joined up
with it.

So, I'm doing my thing, checking the waveguide, when the Guidry pulled
out of her dock and started a series of manuvers on the Mississippi.
As it happened, I had narrowed down the problem to a connection at the
radar mast so I climbed the tower and just as I reacherd the top, the
river pilot put the Guidry into a hard starboard turn.

It was early June - the river was at flood and the Guidry went up on
it's rail with a screaming engineer hanging off the tower looking down
at 'Ole Muddy from a height of 9 feet when he had been looking at 'Ole
Muddy from a height of 50 feet.

After what felt like eight hours, but more more like 30 seconds, the
Guidry came upright, but there were some highly ****ed off yard
workers, owners and one REALLY ****ed off engineer.

Alls well that ends well I guess, but I still remember that like it
was yesterday.

Later,

Tom
S. Woodstock, CT
-----------
"Angling may be said to be so
like the mathematics that it
can never be fully learnt..."

Izaak Walton "The Compleat Angler", 1653

"otnmbrd" wrote in message
hlink.net...


Lawrence James wrote:
http://www.naval.com/heavy-seas/3/

If you examine the first picture and the next to the last picture
showing
the huge wave on this page very closely you will figure out that the
next to
the last picture is a hoax. Look closely at the details of the boat in
the
first picture and closely at those identical details on the next to the
last
one. Look at the water detail around the rear of the boat, identical.
The
hoax picture appears on one of the other pages too.

This one has been argued in numerous NG's. The general feeling is that
you are correct.

So what is the consensus on measuring a wave. Do you measure from the
average water height to the top of the wave? Or from the bottom of the
preceeding trough to the top of the wave?

Bottom of trough to top.

A 60 ft high ship can easily have a 30 foot wave break over it if the
back
of the ship is still on top of the prior wave and the nose is in the
trough.

A good number of ships, exceed the wave length, and don't forget, they
are "driving" through, so, it's not all that uncommon between the
pitching and driving force, to take a wave over, but basically, you are
correct.

otn


A major problem with large ships is the wave length related to the length
of the ship. In the Bering sea, the wave heights can exceed 200' and the
ship will try to be supported only by the bow and stern. Makes for a broke
in two ship. There are some experiments with satellite radar to measure the
seas, to avoid the ship getting in this predicament.
Bill

DSK wrote:
K. Smith wrote...

Before you knee jerk have a good look at the pics & you'll see that
there is not likely to be a 30ft wave there in any of them


Uh-huh. Please explain how a wave of less than 30 feet is going to roll
clear over the bow of a large ship with approx 60 feet of freeboard.

The boat displaced 10s of thousands of tons. it actually is traveling
downhill on the back of the last wave & rather than the wave being
bigger (higher) than the bow the ship's just ploughs through it. Even in
almost flat water is a big boat is going straight into the swell it goes
through it rather than over it.


Well found properly handled small boats in open water have little the
fear from any of that.



Don White wrote:

You may have no problem, your derelict tub run aground in some backwoods
swamp on the Gold Coast.
People who get out on the real ocean say different.



Yes, it's pretty clear that "K. Smith" knows little about this. Maybe
it's wishful thinking?

Not wishful thinking but plenty of time on yachts in my younger days &
always amazed at how it can blow hard for 3 days yet no huge waves,
why?? because the higher a wave the longer the distance between crests,
so even a large swell is no worry to smallcraft, the wind waves on top
can be nasty but again well found & handled not dangerous.


I often hear the crab-crusher guys talking about their ideal of an
"All-weather go-anywhere" cruiser... and think about the North Atlantic
storm that a USN destroyer went through, while I was on it... caused a
couple million dollars of damage, ripping up 1 1/2" welded steel
fittings and sending water flooding in the forced-draft blower intakes
(among other things).... and I don't think any small boat is going to
survive that other than in pieces. Not to mention that the people in it
wold be pulped against the cabin sides.

Yes they "drove" the boat into the waves with endless HP so what???
Those same apparently breaking waves would have just melted under a
small craft, again look closely at the pics & wonder why ANY with an
horizon in them suddenly show what's really happening.

Sorry, but reality is what it is, not what you wish it was.

I'm happy to explain how the stories get created by people who have no
understanding of how on a wave the acceleration is in many directions up
& at an angle at once, this means unless you have a clear view of a hard
horizon you cannot in any circumstances estimate the height of the waves
& in storms you will not see a hard horizon even from a ship, just
spray, much less seeing an horizon from a small craft.

As for Rick he's just a liar like Harry been shown here often enough;
he's full of BS nothing more.

K

Fresh Breezes
Doug King

Short Wave Sportfishing wrote:
On Tue, 16 Mar 2004 23:08:02 +1100, "K. Smith"
wrote:


Calif Bill wrote:

http://tv-antenna.com/heavy-seas/




Hmmm contrary view has to be put & as always only too happy to discuss
it:-)

Thanks for the pics though, they prove yet again that "huge" waves in
open water are the stuff of over active imaginations


Ummmmm....ok, I'll bite.

Why?

Look at the pics, some show a wave seeming to be breaking "onto" the
boat?? whereas in reality the boat is ploughing "through" & in part
creating the wave, waves don't break like that in open water until they
get disturbed by the proximity of the ship's displacement.

In a couple you can see the boat is on the downward plunge so the
"apparent" huge wave doesn't exist at all, in others the wave is getting
on board, however as a rough (little pun the-)) rule of thumb waves
start to stand up when they get close to objects, rocks, beaches reefs
etc & the wave sees the ship as a blockage to the flow of the wave's
energy (it's only the energy that flows in a wave not the water itself,
the water itself mostly just scribes a small circular motion as the
wave's energy passes), so just as with every other time that happens the
first thing is the wave stands up higher, after a point (usually when
the height is the same as the depth of the obstruction) it can no longer
"stand" & breaks, once it has broken then the energy is released & the
water does move.

A good example is a couple of pics from a ways off that show ships &
the horizon behind??? as you can see in one (the tan coloured hull) the
ship is pitching well & truly, the bow is well up exposing almost all
the forward draft (the boat is pitched stern well down in the trough,
but the onboard crew wouldn't know that), the actual waves in the
vicinity are not all that big??? If you quizzed the crew they'd all
swear black & blue tall tales & true.

It's not that they're liars as such, although our own pet Rick is:-),
it's a trick of the eyes input vs the inner ear balance, the reason we
get seasick, the reason untrained (instrument) pilots can't fly in cloud
without unconsciously going into a big slow spin till the ground
intervenes even though they would & do!! swear they're flying straight &
level despite the screaming engine, the spinning instruments so strong
is the belief in our own balance system & it's the reason nasa give
their astronauts an artificial horizon reference to concentrate on.

Your eyes are the primary inputs we get attuned to & in most
circumstances what we see coincides with what our inner ear says, as
regards motion.

Once we loose a standard reference like an horizon then the inputs from
the inner ear can create deception. I boat in heavy weather is a myriad
of constantly changing accelerations, up, down, roll & pitch & when you
have no reference you imagine what your eyes are saying is correct but
not so. Again see the pics with a clear horizon in the backgrounds
suddenly the waves look modest.

At sea in heavy weather you're usually running (got not much choice on
small yachts:-)) & invariably someone comes up from below & looks astern
only to see the mythical huge wave standing up about to break upon the
boat, what this person is actually looking at is down the back of the
wave that just past under the boat, through the trough then up the steep
face of the next approaching wave, however having no reference other
than the confusion of their own balance he/she in all honesty "sees'
that all as all up & the face of an approaching huge wave.

A good "test" to try on a bumpy day is to "estimate" the swell height,
from the lower deck where you can't see the horizon, then climb to
whatever height it takes so you can still see the horizon in the
troughs, your eye height above the waterline is the real wave height,
you'll be astounded because rarely will you not see an horizon in the
troughs just standing on your normal aft deck, what?? eye height 6-7 ft.

Ships are so big it's even worse because you have so many apparently
fixed references around you, the ship "seems" immovable & therefore it's
easy to misconstrue the waves as all being "up" as if the ship is
floating in a harbour. The big wave pics out over the bow with no
horizon visible??? the boat is actually pointing well downhill the stern
still being on the last crest, but with no horizon you wouldn't know
that even if you were aware of the fact & looking for it, because as Mr
Einstein said gravity is just acceleration & our balance system is
designed to sense acceleration only. Ships in heavy weather rise up,
down, roll & pitch the same as & if being powered even slightly "into"
the weather even more so, than smallcraft, the rub is their mass/length
dictates they go through many waves rather than over them.


K


Later,

Tom
S. Woodstock, CT
-----------
"Angling may be said to be so
like the mathematics that it
can never be fully learnt..."

Izaak Walton "The Compleat Angler", 1653

On Wed, 17 Mar 2004 18:58:11 +1100, "K. Smith"
wrote:

Short Wave Sportfishing wrote:
On Tue, 16 Mar 2004 23:08:02 +1100, "K. Smith"
wrote:


Calif Bill wrote:

http://tv-antenna.com/heavy-seas/




Hmmm contrary view has to be put & as always only too happy to discuss
it:-)

Thanks for the pics though, they prove yet again that "huge" waves in
open water are the stuff of over active imaginations


Ummmmm....ok, I'll bite.

Why?

Look at the pics, some show a wave seeming to be breaking "onto" the
boat?? whereas in reality the boat is ploughing "through" & in part
creating the wave, waves don't break like that in open water until they
get disturbed by the proximity of the ship's displacement.

~ snippity snip ~

Interesting.

Later,

Tom
S. Woodstock, CT
-----------
"Angling may be said to be so
like the mathematics that it
can never be fully learnt..."

Izaak Walton "The Compleat Angler", 1653

On Tue, 16 Mar 2004 22:08:11 GMT, "Lawrence James"
wrote:

http://www.naval.com/heavy-seas/3/

If you examine the first picture and the next to the last picture showing
the huge wave on this page very closely you will figure out that the next to
the last picture is a hoax. Look closely at the details of the boat in the
first picture and closely at those identical details on the next to the last
one. Look at the water detail around the rear of the boat, identical. The
hoax picture appears on one of the other pages too.

So what is the consensus on measuring a wave. Do you measure from the
average water height to the top of the wave? Or from the bottom of the
preceeding trough to the top of the wave?

A 60 ft high ship can easily have a 30 foot wave break over it if the back
of the ship is still on top of the prior wave and the nose is in the trough.

Ok, good points, but I'm confused by this last exanmple.

Later,

Tom
S. Woodstock, CT
-----------
"Angling may be said to be so
like the mathematics that it
can never be fully learnt..."

Izaak Walton "The Compleat Angler", 1653

G Picture a submarine, diving.
Judging wave heights, at sea is not easy. On a ship, judging heights up
to @30-40' can be done with reasonable accuracy (the bigger the ship the
better), but above that it becomes much more difficult.
If you read various books, I believe you'll find that @60' is considered
the maximum that waves can reach at sea. I feel the number is
considerably higher, but no where near 200'.
It's kinda like reporting roll angles with a "clinometer" .... "we were
rolling 40 deg by the clinometer" .... in truth, their roll angle was
closer to 20 deg.

otn

Short Wave Sportfishing wrote:


A 60 ft high ship can easily have a 30 foot wave break over it if the back
of the ship is still on top of the prior wave and the nose is in the trough.


Ok, good points, but I'm confused by this last exanmple.

Later,

Tom
S. Woodstock, CT
-----------
"Angling may be said to be so
like the mathematics that it
can never be fully learnt..."

Izaak Walton "The Compleat Angler", 1653

According to the Government they figure 200' swells possible in the Bering
sea area. Spent a few deficit dollars looking at them with satellite radar
to figure out how to measure and keep ships out of their path.

"otnmbrd" wrote in message
hlink.net...
G Picture a submarine, diving.
Judging wave heights, at sea is not easy. On a ship, judging heights up
to @30-40' can be done with reasonable accuracy (the bigger the ship the
better), but above that it becomes much more difficult.
If you read various books, I believe you'll find that @60' is considered
the maximum that waves can reach at sea. I feel the number is
considerably higher, but no where near 200'.
It's kinda like reporting roll angles with a "clinometer" .... "we were
rolling 40 deg by the clinometer" .... in truth, their roll angle was
closer to 20 deg.

otn

Short Wave Sportfishing wrote:


A 60 ft high ship can easily have a 30 foot wave break over it if the
back
of the ship is still on top of the prior wave and the nose is in the
trough.


Ok, good points, but I'm confused by this last exanmple.

Later,

Tom
S. Woodstock, CT
-----------
"Angling may be said to be so
like the mathematics that it
can never be fully learnt..."

Izaak Walton "The Compleat Angler", 1653