I've never been to Sea World. I was just assuming we would do what we are planning to do in Disney and Universal- get there when it opens, leave at about 3 or 4 for "Linner" (the boys love that phrase) and go to a regular restaurant nearby, then go back later in the day.
Of course, I don't know if you can leave and re-park, or if there is anything close by, but I still have a few days to plan this thing!