It really depends on what you want to do. You can go JetSkiiing on the bay. Take a dinner cruise, sunset cruise, take a beach day on one of our many beaches. The is a small seaside amusement park called Belmont Park not far from Seaworld (about a 5 minute drive with no traffic.) San Diego is also a major city, with city things to do, like shows, museums, and clubs if you are into those types of things.