We've been to two Texas Pirate Festivals - one in Hillsboro and one in The Colony. I don't think either is still in existence, and the fact that neither is within a few hundred miles of the Gulf may have something to do with it.
The Texas Pirate Festival near Hillsboro was at Middlefaire, which hosted many festivals. It seemed like a Renaissance Fair but with "Arrr!" after most sentences. It was fun, but I think the high point was getting kolaches at Slovachek's on the way home. I can't find any photos, so the mead must have been tasty.
The Texas Pirate Festival in The Colony was a Celtic music festival with "Arrr!" after many sentences and sea shanties.
There are other Pirate Festivals in the State, so this page will need updating.