On Wed, 22 Jan 2014 20:45:04 -0500, "Mr. Luddite"
wrote:

That particular encounter with the tugs and barges has always remained
in my memory banks. I can recall it like it was yesterday. I initially
tried more distance but the depth gauge alarm would go off very quickly.
The whole time we were passing both barges I had one eye on the depth
gauge and one on our relative position to the barges. The Navigator
drew 4.5 feet. I had the depth gauge calibrated to include a little
safety factor and I remember it sometimes reading under 4 feet.

The space I had to maneuver was less than the width of my boat. Even
being that close to the barges, the alarm would go off a few times.
Nerve wracking.

===

It's sort of like driving on a one lane road where you try to find a
wide spot where you can pull over and wait for oncoming traffic. The
problem is that there aren't that many wide spots and you don't get
enough warning that a tug/barge is coming. Technology is beginning
to help out a little bit however. Virtually all tug boats have AIS
transponders these days that reach out 10 to 20 miles. When we come
north this spring we'll be equipped with an AIS receiver that
identifies the type, speed, location, size and name of uncoming
vessels. Hopefully it will give us a bit more warning time for
finding a wide spot.

http://en.wikipedia.org/wiki/Automatic_Identification_System