I saw on the sea world website that you could get a child annual pass for half price with an adult annual pass for sea world and aquatica. We're also interested in busch gardens annual passes. I'm trying to figure out if I could get half price pass and then upgrade that to include busch gardens. The answers from the seaworld phone number are a little cryptic. I was told they could do it but they wouldn't know a price until I actually did it. I just don't want to end up having to spend more than what the annual passes for all three parks would cost if I bought the 3 park pass. Any ideas or insight or experience? Thanks.