On Sun, 23 Nov 2003 23:44:10 +0000, Rodney Myrvaagnes wrote:

On Sun, 23 Nov 2003 15:54:00 -0800, "Lloyd Sumpter" wrote:



Thanks for the input!

I didn't mean an either/or scenario - it's more like: if I have
GPS/sounder/charts, what extra does radar give me? And of course, it DOES show
vessels, etc., but I'm thinking that's mainly a consideration in fog, and I'm
wondering if I would venture out even if I HAD radar (after all, what if the
radar quits?).

So is radar worth it for the 1 day a year I MIGHT venture out in fog?

Or, to put it differently, what ELSE is radar good for? Can I use it to
determine if a freighter 10 miles away is on a collision course with me? Do
others normally run with radar on, even if it's clear? Why?


That is actually a different question, because a radar has value for measurement
even when you can see.

Example 1: If you need to anchor in a confined space, and the obstructions all
show on the radar, you can maximize your scope by finding the center of a range
circle that just kisses the three nearest obstructions.

2) Your chart shows you the safe distance from a headland. You put a circle of
that radius on the screen. and steer so it doesn't intersect.

3) When you see a ship, you can put a bearing line on it and a range circle. If
the ship comes inside the circle without moving off the bearing line you need to
take action.

In general, you will find that an accurate plan view of the surroundings is a
valuable supplement to eyeballs.



All Great Information - thanks everyone!

A couple of points I see that I hadn't seen before. One is night: I do
occasionally sail at night, and it would be great to see the boats/ships rather
than squinting at little lights (esp if they're towing things, which is very
popular here on the coast. Anybody know if radar could pick up a log-boom?)

Also, measuring distance from objects. Good point. Last time I was out, I needed
to clear some rocks before making my turn - GPS is OK for that, but radar would
have made it easier.

And the point about practice I already thought about: If I'm only using it a few
times a year, thick fog is NOT the place to figure out how it works!

Final question: if the fog was thick (vis. maybe 100 ft) and you had radar (and
GPS, etc) would you go out?

Lloyd Sumpter
"Far Cove" Catalina 36