Thanks everyone for the responses!

I'm about to start googling trains but DH is now thinking if we hire a car for Day 1 and Day 5, we might as well get one for Day 1 - Day 5. That way we have freedom for dinners as well, won't be confined to the resort and if we get sick of Sea World we can go check something else out. Found a pretty cheap car rental place too, East Coast Car Rental, anyone used them?

Going to check train prices...