I live in Galveston. Tremont and Harbor House are walkable to port. If there are too of you and you are flying into Hobby, just take an Uber to the island. It will be around $50 and easier than waiting for the cruise line bus and most likely cheaper. If you have the funds Tremont is right in the action, great bar. Another classy option is Galvez on the sea wall. There is no commercial service into Galveston airport