The correct term of these sales tax is usually "sales and use" tax. If you don't owe the tax duye to the sale, then the state hits you with the same tax for the "use". If Texas is like most other states, they check marinas and boatyards for lists of boats physically present, the check to see the boats have paid the sales/use tax. If not, they'll charge the taxc plus interest and penalties. If you're there for even a few months, you should consider paying it.
Certified...in several regards...