On Thu, 19 Mar 2009 21:05:42 -0700 (PDT), Frogwatch
wrote:

Do trim tabs at the transom accomplish the same thing? I assume they
are used to get the boat on a plane faster than without them thus
effectively making it a smaller deadrise.

It depends on the size of the tabs. I use them that way on our
runabout and it does help keep the stern from digging in when you want
to jump on plane in shallow water. Once on plane however the boat is
faster without them indicating less drag. There are other uses of
course such as controlling bow inclination and leveling out side to
side trim. Our old Bertram 33 sportfish had a lot of deadrise carried
all the way aft. I installed oversized trim tabs in the hope that it
might improve fuel economy but it didn't seem to have much effect.