I go down and fish for the Reds and Trout one or two times a year. My son lives down there so we visit and I fish. We are in the Port O'Conner area.
Don't give up on the fishing down there it will take a time or two to understand how things work and to find good fishing spots. The tides are real important. I found that if you could find cuts and fish them when the tide is going or coming that you can catch fish in them. The fish hold there waiting for the bait to be washed to them. You can also rent Kayak's down there and they sure help you cover water and find fish. Look for working birds or slicks on the water. You can see these at a distance and they will point you to fish.
I also might advise taking a guide a time or two. They will teach you a lot and you will learn spots to fish plus you will porbably catch some fish for dinner. I keep a few to eat while I am down there as they are sure good. I like flounder they are just great eating. I catch a lot of these fishing around some docks in one area were the channel comes up close to them. Just get the fly close to the bottom and keep it there.
One other thing for you to try is fishing piers at night under lights. You can do real well then to.

A book that you might like to read is "Fly Fishing the Taxas Coast" By Chuck Skates and Phil Shook. Good information and also a good read. You might also get a "Top Spot" map of the area you will be in. Lots of great information on those maps and they show places to fish and just about all the information for that area a person would need to fish that area.
If you need overhead pictures of the area you want to fish to get an idea of what it looks like let me know and I will post a site for you to get them. Hope this helps. Ron