Sometimes the rock groins on the seawall on Galveston Island is a good place. You'll have to check with the tides. Incoming tide is the best, at least it is for me, for crabs.
When the water gets about 70 degrees hopefully around April 1st, I'm going to try a new place in Baytown I've never been to called Roseland Park.
http://www.baytown.org/content/roseland-park