SeaWorld San Antonio is a full-scale theme park rather than a quick city attraction, combining marine-life shows, aquariums, roller coasters, water rides, and seasonal events. It sits well outside the historic centre, so it needs its own day and transport plan.
For many independent travelers it will be optional, but families often build a San Antonio trip around it. Check schedules before going, because show times, water-park operations, and seasonal events change the shape of the day.