On Aug 11, 3:43 pm, otnmbrd wrote:
" wrote groups.com:
....

OTNM, you raise good points, and I've made some sweeping statements
and moved freely between Skip's particular case and cases in general.
Also, I get the feeling we may be talking about different conditions.
My experience has largely been in international waters far offshore
and may not really apply to more typical near coastal conditions.
Anyway, with that in mind:

[] As nearly as I can make out fishing vessels
never keep any watch at all, but even commercial carriers are pretty
bad about watch keeping at sea.

Based on what first hand knowledge?

I read the incident reports in the backs of the trade mags. I also
have friends in the marine trades and merchant marine and friends who
make their living as fisheries observers and friends who are serious
small boat voyagers. They all tell tales. I've also worked for a US
shipping company, but in IT and all I can attest to from that is that
some ship's officers in US domestic trade spend a lot of time reading
and creating reports while at sea. For the last year or so I've been
working out of my pilot house and have had a VHF monitoring most of
bridge to bridge traffic in the Honolulu area and I'd guess that as
much as a third of all attempts to get passing agreements fail because
one party isn't keeping watch (the navy is particularly inept at
this). But that's all second hand. My first hand knowledge is in
small boats so I can't report on what is actually happening on the
bridges except when we pass close enough to see into them, but I can
report on what seems to be happening from the small boat operator's
point of view. I've spent a good deal of time offshore doing delivery
work, racing and six years of full time long distance cruising that
included three circuits of the pacific and it has become my custom to
hail most contacts on the VHF when offshore. My feeling from this
unscientific survey is that even of those vessels professional enough
to keep a radio watch few if any keep a continuous and careful visual
and radar watch when off soundings.
....
Leaving the RADAR on 24 miles is a
mistake.

Yes and no..... for ships, one set on 24, one on 12 with occasional
shifts down is great.... offshore for small boats, leave it on 12 ( you
should still see any closer targets if you know how to use the radar)
with occasional shifts down in reduced vis.

I agree that 12 is the best compromise for most small boats and small
radars offshore, but you should change scales regularly. It has been
years since I took my radar training and technology has improved but I
recall that continuous long range scanning was considered very bad
form (maybe even illegal in the context of watch keeping). Even if
the new digital sets have made this better it is still going to be
easier to see small, close targets on the closer scales at the very
least because they will be bigger blobs on the ppi.

....
[] Most targets will not show at 24 miles and closer targets
may be lost in the clutter. Also intermittent targets will only be
evident if you watch the ppi closely for several scans.

Again, yes and no.... depends on your system....etc.
....
[] In clear weather I've found that we almost
always make visual contact on small targets before we see them on
RADAR.

G Again, depends on your system

True. The context I was thinking of when I wrote those comments was
offshore using a small, unstabilized, analogue radar of the type
typically fitted to yachts.

-- Tom.