renewontime dot com wrote:
snip
Second, what speed ships operate at runs the gammut, but what I consider
to be the "big guys": super containerships, tankers and cruise ships,
normally run around 32-36 knots.


Really? I just did a quick google, and apparently QM2 is "The Fastest
current ocean Liner apart from QE2 (approx 30 knots vs. 32.5 knots )" so
which particular cruise ships (etc) do you have in mind?

Andy

Andy Champ wrote:

renewontime dot com wrote:

snip
Second, what speed ships operate at runs the gammut, but what I
consider to be the "big guys": super containerships, tankers and
cruise ships, normally run around 32-36 knots.


Really? I just did a quick google, and apparently QM2 is "The Fastest
current ocean Liner apart from QE2 (approx 30 knots vs. 32.5 knots )" so
which particular cruise ships (etc) do you have in mind?

Andy


G I say his speed were a bit high.
I'd give average speed range between 14-20, with all tankers falling in
the middle to lower part of that range and some of the others capable to
@26-28K, and always the exceptional few in the low to mid 30's.

BTW Merchant ships don't have to head to the nearest port when a radar
goes down, but must report it prior to arrival at the next port and
repair before departing .... at least, in the US.

otn

renewontime dot com wrote:

Let me try to clear up some serious misconceptions:

First, your "visible horizon" depends on two things: height of eye and
your atmospheric visibility. With a height of eye of 8 feet (rough
guess of your height of eye on a small yacht) your visible horizon in
clear conditions is roughly 3 miles. To calculate how far you might see
a "big ship", you'd add the distance of the horizon for the ship's
superstructure (say 9 miles for a 60 foot high ship). So in this case,
the furthest you'd be able to see this ship is roughly 12 miles, and
quite possibly alot less than that. If you don't believe me, look it up
in Bowditch.

I figure that most cruising sailboats, even those keeping a good
lookout won't spot a white superstructure at 9 miles but will probably
spot a hull at 5 or so miles.

I agree that atmospheric haze often limits visibility *even* if you
don't notice it.

Second, what speed ships operate at runs the gammut, but what I consider
to be the "big guys": super containerships, tankers and cruise ships,
normally run around 32-36 knots.

Nobody in the commercial fleet runs at 32-36 knots, especially not
tankers! The very fastest container ships and LNG carriers are
around 25-27 knots. Cruise ships are slower, around 22-23 knots top
speed and most tankers are slower still. The exception would have to
be the SL-7 Fast Sealift ships which did 33 knots on trials.

Third, it's been my experience (30+ years at sea) that almost every
merchant vessel at sea maintains a -very good- watch and lookout. There

Not in my experience. I've often called up passing merchant vessels
at sea on VHF 16 and it usually takes several calls for about 10
minutes before _some_ will reply. I've asked how my visibility on
radar is and got the reply: "let me warm it up....".

The problem for merchant ships is that small sailing vessels are just
hard to see. VERY hard to see. They usually present a poor RADAR
target and have dim or no navigation lights.

Agreed. We're small targets.

Fourth, by law all ocean going merchant ships are required to be
fitted
with and operate their RADARs. If a ship has a RADAR failure, they are
required by law to head directly to port and not get underway until it's
been fixed (there's more to it than this over simplification, but I'll
spare you the details). I know of no ship's master that would risk
his/her license and livelyhood by allowing their RADARs to be secured
while operating at sea. Your comment to the contrary is complete nonsense.

See my post above. I think a lot of flag of convenience ships don't
have their radar on all the time, probably to save the cost of
replacing the magnetron.

But I think we agree that cruising sailboats are small, hard to see
targets, that large vessels are often not seen until they are within a
few miles of you, and that everybody should keep a good lookout.

Having said all that, I don't think single handed sailboats pose much
of a risk to anybody, with the exception of fast racing yachts
(wouldn't want to be hit by B&Q at 30 knots)

Evan

I figure that most cruising sailboats, even those keeping a good lookout
won't spot a white superstructure at 9 miles but will probably spot a
hull at 5 or so miles.

The numbers I used were "best case" scenario straight from Bowditch.
The reality is that most sailors will likely spot a surface contact at
ranges more like what you've shown.

Nobody in the commercial fleet runs at 32-36 knots, especially not
tankers! The very fastest container ships and LNG carriers are around
25-27 knots. Cruise ships are slower, around 22-23 knots top speed and
most tankers are slower still. The exception would have to be the SL-7
Fast Sealift ships which did 33 knots on trials.

I didn't mean to imply that -all- big ships operate at speeds over 30
knots, I was trying to make a point in reply to the original posters
question and some of the misconceived replies, ie. "at least an hour
will pass from when I see a contact on the horizon to when it will hit
me". My point is that ships at sea operate at a wide variety of speeds,
even in excess of 30+ knots, and as a cruiser you need to be aware of
this. As for "high speed" ships out there, I think you guys are off on
this. All the newer ships are being built to operate at 30 knots or
greater. There are a number of "fast" container and oil carrier ships in
the works, and shipbuilders are starting to deliver "fast" ferries that
will operate at 40+ knots. And it won't stop there, I've read that the
designers have plans for ships that will operate at 50 to 60 knots.

See my post above. I think a lot of flag of convenience ships don't
have their radar on all the time, probably to save the cost of replacing
the magnetron.

That's not been my experience at all, but you're welcome to believe what
you want.

--

=-------------------------------------------------=
Renewontime
A FREE email reminder service for licensed mariners
http://www.renewontime.com
=-------------------------------------------------=

"renewontime dot com" wrote in message news:

I didn't mean to imply that -all- big ships operate at speeds over 30
knots, I was trying to make a point in reply to the original posters
question and some of the misconceived replies, ie. "at least an hour will
pass from when I see a contact on the horizon to when it will hit me". My
point is that ships at sea operate at a wide variety of speeds, even in
excess of 30+ knots, and as a cruiser you need to be aware of this.

Very true

As for "high speed" ships out there, I think you guys are off on
this. All the newer ships are being built to operate at 30 knots or
greater. There are a number of "fast" container and oil carrier ships in
the works, and shipbuilders are starting to deliver "fast" ferries that
will operate at 40+ knots. And it won't stop there, I've read that the
designers have plans for ships that will operate at 50 to 60 knots.

The number of ships of any type running at 30+K is small and will remain so
for some time. Biggest problem becomes HP to get them to that speed versus
fuel consumption. (one reason the the previously mentioned SL-7"s are now
all US Gov.... they're the only ones who can afford or justify running
them).
High speed ferries, on the other hand, running in the high 30's are becoming
"a dime a dozen".
Newer technologies, as you say, are on the drawing boards.

See my post above. I think a lot of flag of convenience ships don't
have their radar on all the time, probably to save the cost of replacing
the magnetron.

That's not been my experience at all, but you're welcome to believe what
you want.

G I'm probably in between both of you on this.
First off, the problem is less "flag of convenience" and more "owner,
operator".
Since ships all have at least 2 radars, both of which are at least on
"standby" at sea (exceptions noted), coupled with ever increasing
enforcement and penalties for non use, the old "magnetron" excuse is falling
by the wayside.
However, it's not a perfect world and there are still too many fools out
there running with radars turned off in open ocean conditions.

otn

renewontime dot com wrote:
snip
I didn't mean to imply that -all- big ships operate at speeds over 30
knots, I was trying to make a point in reply to the original posters
question and some of the misconceived replies, ie. "at least an hour
will pass from when I see a contact on the horizon to when it will hit
me". My point is that ships at sea operate at a wide variety of speeds,
even in excess of 30+ knots, and as a cruiser you need to be aware of
this. As for "high speed" ships out there, I think you guys are off on
this. All the newer ships are being built to operate at 30 knots or
greater. There are a number of "fast" container and oil carrier ships in
the works, and shipbuilders are starting to deliver "fast" ferries that
will operate at 40+ knots. And it won't stop there, I've read that the
designers have plans for ships that will operate at 50 to 60 knots.


Fascinating. I'd like to learn more - can you point me at any web
sites? I can't find anything much over 25kts.

Thanks

Andy.

I missed this one:

Not in my experience. I've often called up passing merchant vessels at
sea on VHF 16 and it usually takes several calls for about 10 minutes
before _some_ will reply. I've asked how my visibility on radar is and
got the reply: "let me warm it up....".

I won't try to make excuses for how others may stand their watch (and
yes, I've got my share of similar stories), but would only suggest that
there are other possible reasons for why you aren't getting responses to
your hails on 16, including the possibility that they did not receive
your hail, the watch officer didn't speak English, or that they decided
it wasn't necessary to respond.

--

=-------------------------------------------------=
Renewontime
A FREE email reminder service for licensed mariners
http://www.renewontime.com
=-------------------------------------------------=

"Evan Gatehouse" wrote in message news:

Third, it's been my experience (30+ years at sea) that almost every
merchant vessel at sea maintains a -very good- watch and lookout. There

Not in my experience. I've often called up passing merchant vessels at
sea on VHF 16 and it usually takes several calls for about 10 minutes
before _some_ will reply. I've asked how my visibility on radar is and
got the reply: "let me warm it up....".

Couple points here to keep in mind.
On most ships, English is not the "first" language and the quality of
"English" lessens as you go from Master to 3rd Mate.
If you run across a ship that doesn't have at least one radar running,
normally you will find that they will be on standby, which means no
"warm-up" needed. However, depending on the set, there's a good chance that
the set itself will not be set on a range where you will be seen if you are
close (at sea range, 12 or 24 mi.) so adjustments will be, or may be
needed.
Also, keep in mind that depending on the radar in use (10cm or 3cm) in some
conditions you may not be visible at all due to sea return or age and
condition of the set, plus the particular operators abilities.
Radar is no more foolproof than anything else, so just because one ship says
he has no problem or a great problem seeing you, doesn't mean ALL will have
the same results, even under the same conditions.


otn

Evan Gatehouse wrote:

Nobody in the commercial fleet runs at 32-36 knots, especially not
tankers! The very fastest container ships and LNG carriers are
around 25-27 knots. Cruise ships are slower, around 22-23 knots top
speed and most tankers are slower still. The exception would have
to be the SL-7 Fast Sealift ships which did 33 knots on trials.

I am not sure where you operate, but it's worth noting that there are a
number of situations where one encounters commercial vessels that routinely
operate at greater than 40 knots.

I have been sailing Bay of Fundy for quite a few years now. This is an area
where fog is common, and also an area where the "cat" ferries transit from
the US over to Nova Scotia. These beasts are over 300 feet long and have a
cruising speed of near (or perhaps over) 50 knots.

Several people have been killed by them in the past few years. Indeed, I
had the devil of a time getting the attention of the Bar Harbor - Yarmouth
ferry in high visibility conditions in one particular instance. The last I
heard there was a lot of pressure from operators to add this type of service
in Long Island Sound, a very high traffic area.

--
Good luck and good sailing.
s/v Kerry Deare of Barnegat
http://kerrydeare.home.comcast.net/

Armond,

Those are "high speed ferries", not ships. They involve a whole different
set of operating parameters than ships, including stopping distance.
In dealing with them and discussing them, you need to realize and understand
that comparing them to normal commercial traffic is comparing "apples to
oranges"....., same applies to standard tugs and Z-drive or Voight
Schneider.

otn

"Armond Perretta" wrote in message

I am not sure where you operate, but it's worth noting that there are a
number of situations where one encounters commercial vessels that
routinely
operate at greater than 40 knots.

I have been sailing Bay of Fundy for quite a few years now. This is an
area
where fog is common, and also an area where the "cat" ferries transit from
the US over to Nova Scotia. These beasts are over 300 feet long and have
a
cruising speed of near (or perhaps over) 50 knots.

Several people have been killed by them in the past few years. Indeed, I
had the devil of a time getting the attention of the Bar Harbor - Yarmouth
ferry in high visibility conditions in one particular instance. The last
I
heard there was a lot of pressure from operators to add this type of
service
in Long Island Sound, a very high traffic area.