Try an aerial search with Google Earth
. I did just for a few minutes and only saw one location that might have been a recreational marina, near the airport
on the bay side of the island. It does look like an interesting area, and it would seem you might be able to find some places in the mangrove lined estuaries to secure the yacht during the storms that sweep through each year. I think I'd spend some time there before taking the yacht down, however.
I make it about 685 miles (nautical) from Houston
which would likely take you about 6 days on a relatively smaller yacht.