Try these guys:
https://www.hagerty.com/Insurance/Cl...Boat-Insurance
They have local agents or you can go direct. You need a recent
survey and list your
experience with
boats. I assume
Texas has a state boaters card. You'll need that unless you have professional papers.
I use them because they've been competitive and cover US and
Canada to 25 miles out as a base rate. My stomping grounds. I often go more than 25 miles, but I take the risk instead of a rider.