On Tue, 24 Feb 2009 21:58:27 -0600, Vic Smith
wrote:

For instance if you couldn't back off, and it was near high tide,
would you try to kedge off?

It's difficult enough to kedge off a 5,000 lb boat, almost impossible
with 70,000 lbs. We try to avoid marginal water depths at high tide,
it being much more preferable to go exploring on half tide and rising.
If you are going slow and nudge the bottom it is usually easy to back
off. Otherwise the best strategy is to try and turn the boat towards
deep water and power it off. A dinghy with a large outboard can be
used as a mini tug boat to turn the boat in some cases. I know one
guy who is a full time cruiser on a boat with an 8 ft draft. He has
a 35 horse on his dinghy just for that purpose. It can be tempting to
try and power through a shallow spot but that can lead to big trouble
if it doesn't work out.