Wayne, there is some excellent fishing in the Aransas Pass / Port Aransas area, easily accessable by kayak (Sorry Castwell). Check with Slowride (Dean Thomas) in Aransas Pass. He's not only a great source of information, but he'll also line you up with a yak. Here is his link, along with a couple of others that might be of interest.

Tight lines, Chris

http://www.slowrideguide.com/

http://www.coastalkayakfishing.com/

http://www.texaskayakfisherman.com/