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