For that area of the northern gulf you will need to go out about 100 nm give
or take a few. You may not find type of trip well suited to your boat. About
the only place in the northern gulf where the 100 fathom curve is relatively
close to shore is out of the mouth of the Mississippi river out of the port
of Venice LA. In Venice the curve is more like 12-14 nm out of the river
but this is after a 20 nm trip down the river. However fuel is available at
a marina just at the mouth of the river ( Port Eads). You may want ot look
into chartering a boat that regularly fishes the area you mentioned.
Catch'm up!

--
Ron White
Boat building web address is
www.concentric.net/~knotreel