Galveston is the biggest cruise port in Texas, and on the Gulf Coast as well. It offers year-round voyages.
The vast majority of cruises from Galveston will be 4-7 night Western Caribbean itineraries, though some will as long as 10 nights and have more ports to explore. Typical ports are in Mexico, Grand Cayman and Jamaica.
Cruises that are longer than 10 nights means the ship can travel further and Southern / Eastern Caribbean ports become accessible.
Panama Canal transits to California and repositioning cruises to Europe are also possible, though uncommon.