Ah, the wonders of the Mississippi Sound...dead fish, trash, used con...well, you get the idea.
The Gulf of Mexico really improves clarity-wise once you get past Mobile,AL
...basically, the further East you go, the clearer the water.
Biloxi Beach used to be very popular for beach-goers back in the early/mid 80's (my fam and I used to go there a lot)...of course, the water was nicer back than.
Steve in N.O