Since you get the passes for SW with Discovery Cove visit, you could leave DC when you have done everything you want to do there and head over to SW, but most of the shows at SW happen during the day so you won't get to see very many of the regular shows. At night during the time you are there they have special summer nite time shows for Clyde and Shamu plus a fireworks show. After a day in the sun and the activity at DC you might be really tired and not feel like doing another park, though. To have time to do most of the things at SW you would need to return for at least a 2nd day.