I live in Long Beach, MS.
If you do want to just sit on a beach and get some sand, there are some decent beaches.
You can even get in the water if you want, it never gets much above waist or chest level (depending on the tide) for several hundred yards out.
The MS Gulf Coast has the longest man-made beach in the world, I think, at 26 miles.
It's true that due to the barrier island effect, you won't get the huge waves of other beaches and the water is not blue/green. That's due to all the local estuaries that are on the Coast that provide the breeding habitat for our shrimp and other marine life. The water in the estuaries contains lots of leaves and other decomposing plant matter, which in turn makes the water slightly dark and brown.
But there's nothing wrong with the water, it's like steeped tea. I and my family go in it in the summer and we're all fine, no mutations or disease.
If you have any questions, just ask me!