M.D.
He will love it! We took my son last year when he was two and we're going again next week. It was so much fun to watch how happy he was seeing all the animals!
Anyway, definitely bring your stroller, that will help with naps, etc. Suntan lotion and hats...Sea World doesn't have a lot of shade. Cool clothing...a change of clothing for him too! Also, I personally think Sea World has some of the worst amusement park food and the lines are long and it's expensive. What we do now is the Dining with Shamu lunch. You have to book it ahead of time online or by phone, but it's soooo worth it. Right after or before the show, you have lunch in a buffet style (with food for kids that is free for your son's age), you have drink service provided, high chairs arranged for you before you get there, better food than is in the rest of the park and then the best part...a trainer to answer questions about Shamu and one of the whales swimming around in a pool RIGHT next to where you are eating. It's really great and our son loved it! It was also shaded so that was a nice bonus.
Oh! There is also a new Sesame Street area that opened up...
Enjoy!
-M