ubject: Vessel detectors - radar visibility of your own vessel
From: Rosalie B.


I was driving the boat down along the coast from Ft. Pierce to Miami
at night - trying to keep out of the Gulf Stream and also out of the
zone where the Navy was doing underwater tests (i.e. staying in less
than 100 feet of water) while sailing which meant some tacking. I
could see some ships between me and the shore only because they were
dark shapes against the lights.

Never an easy task.


And one big cargo ship was coming north. I saw the red, white and
green lights. I moved out from shore a bit, but didn't want to go too
far out because of the Navy stuff. Then I saw just the white and
green, so I figured they were going in the inlet. Then they shut off
the green light and appeared to stop. A little bit later they turned
on the deck lights. I guess they anchored or picked up a mooring.

Anchored. If you see a ship heading North, close inshore in that area, he's
(probably) bound for a port or anchorage. Normally, ships Northbound will stay
well offshore in the axis of the Stream.

I've also been at the wheel following a big ship into an inlet, when
the ship stopped and started to back up (in daylight - I don't know
what I would have done at night).

There was a case here in the bay where a cruising boat running up the
western shore at night saw a ship on his radar and saw something else
that he couldn't ID, and apparently went down into the cabin to look
at a chart or get a cup of coffee or something, and he ran between a
tug and the tow and his boat sank within a couple of minutes.

Two errors here (well a bunch, actually).
A tug and tow, is normally an easy radar spot (kinda like a triangle small
target leading a larger one, close together, maintaining a same distance
separation) so poor radar interpretation on his part..... and never leave
the
radar, till you KNOW what you are seeing and what it's doing.

I agree with this, but this tug was towing on a long line and I gather
he made no connection between the two blips. I've also seen tugs
towing stuff like pipes so the tow doesn't have much of a radar or
sight profile at all.

Almost sounds like he was on too low a range scale. For normal viewing, at sea,
I'd suggest 6-12mi (and no lower than 3) to give the best overall picture
(naturally reducing from that if you are working a particular target or feel
the need to check the lower ranges, for numerous reasons).
Most tugs at sea will have 600-1200 feet of cable out (varies), but on the
longer range scales, after some experience, it will still be obvious as to what
they are.

In any case, they lost their boat and everything they owned and were
lucky to escape with their lives, although the Calvert Co Volunteer
Fire Department picked them up out of their dinghy within 15 minutes.

This is a shame, but at least they lived. Many in this case, don't.

Shen