Port Aransas (Mustang Island) - I was there a couple of weeks ago. The water was CRYSTAL CLEAR! I couldn't believe it. Wish I would have had a mask/fins. I've never seen that much marine life on the Texas coast.
I've been fishing off Rockport at times where not only is the water clean and clear, it is actually that turquoise'ish color that reminds you of the carribean. granted, it's not normally like that, but every once in a while it is. and even normally, it's not bad. http://www.lighthousetexas.com/index.shtml is the place to stay, but likely already booked for July 4th. you can probably find some nice places on aransas too.
I was in Galveston this weekend and I noticed the water was very uncharacteristically clean looking. A definite blue tint that I’ve noticed ever since Ike came and went. I almost forgot that I was on a Galveston beach. I wonder if Ike actually washed away all the gunk in the water. Also, the beach was a lot more clean looking as well. And not just the parts where they’ve shipped in sand either.
If you're still looking for things to do and you like baseball, go catch a Corpus Christi Hooks game. The stadium is nice and tickets are cheap.
Shh, stop talking about Rockport, I used to love going there when all there was in town was an old run down Walmart and The Back 40 to eat. My family has been camping Goose Island S.P. all my life, 20+ years, stay the hell out of Rockport. There's nothing for you there.