How about...maybe.
OK, technically yes, there is a shuttle--I've even seen it. When it first started, you had to be an AP to ride it. The rules at Aquatica seem to be constantly shifting tho (hours get extended, early entry goes from weekend to weekday), so that may no longer be the case.
No idea how often it runs, or even exactly where it stops. Because it was "AP-only", last time I checked the tram stop was not even marked. Again, could have been fixed, tho I haven't noticed any signs by SW.
Theoretically, I could see doing a day at SW, then heading over to AQ around 4:00 when the crowds go down. Of course, if we get a lightning storm, that plan goes out the window. Been trying to go over after work for like two weeks now, and it's been storming almost every afternoon.