I haven't seen the article, but I can't see how Texas would rank high. The Gulf Stream pushes flow out of the Mississippi river west and as a result much of the beaches from Galveston all the way to the Louisiana border is made up from a bed of clay mud with a dirty sand covering. The water is dark and murky until you get a considerable way off shore.
Here, (Sabine Pass area) that usually equates to at least 20 miles before the water starts clearing. Sometimes I've seen it bad as far as 40 miles out, and I've dove rigs 60 miles out that still have a layer of murky water at the bottom that is 10-15' deep
In addition, the continental shelf has a very gradual slope. Something along the lines of about 1.5 feet of depth increase for every mile you go out. You've got to go pretty far just to break 100'.
I know that as you go further south down the coast the water improves, as well as the depth but I'm not sure at what point shore diving would become feasible. I've been told Corpus has some decent diving, but it's closer for me to go to Florida, so I've never checked it out.
The one standout that Texas could claim is the Flower Garden Banks National Marine Sanctuary, about 100 miles off the coast out of the Port Aransas area.
If [user]Wookie[/user] sees this thread, I'm sure he can elaborate more because he's done charters out there for years.
Minor correction, that's the Loop Current, not the Gulf Stream.
The Loop Current is formed where the Florida Current and the Yucatan Current combine. It doesn't become the Gulf Stream until later.