Water Taxi Beach and the new farmers' market aren't the only things coming to South Street Seaport this summer. We're told that the owner of the Cowgirl Hall of Fame will open a seafood restaurant at 259 Front Street at the stump of the Brooklyn Bridge. The menu will be Gulf-centric (hush puppies, oyster po'boys, and Abita). The theme will be similar to Cowgirl's, but with a fish-shack slant -- think "rough and tumble fun." Yee-haw.