On Sun, 22 Jan 2006 22:25:31 -0500, Howard wrote:


All that being said, its a cool toy. It may not be worth a damn on a
boat, alone, in the fog, at night.

Very good observations, and since the introduction of Google Earth and
similar services a few months back, I have puzzled over how I could
use it on the boat G.

I think you have to use every tool available to you in the run-up to a
passagemaking or to the transiting of an unknown-to-you landfall or
harbour. These devices are excellent for planning one's approach, but
even in the "live GPS position" mode, they are practically static
compared to the eyes, ears and yes, nose of the practiced sailor. Two
potential problems exist with electronic navigation:

1) With the new expensive, full-colour plotters, you are a little icon
in a video game. This can be isolating you from the dynamic
environment around you. Seamanship isn't a video game, but video games
can aid seamanship.

2) Electronic charts are out of date a day after you get them. Nothing
beats a live, self-interested and therefore motivated human on the
foredeck (using family band radio to the helm if you want to get all
technological) keeping a watch in fog, signalling with a horn and
LISTENING. I have heard of at least one case when sailboats in fog at
night collided because both were converging on the same navigational
aid...thanks to the marvels of GPS/chartplotting. Keeping a watch may
have avoided this.

I have noticed that I can occasionally guess who is using
chartplotting by the behaviour of their boats near navigational aids
or off landmarks following a depth contour. You are the skipper. The
technology informs, but being indifferent to the outcome, it cannot be
responsible.

R.