Right by our hotel was a great little aquarium where the kids (even the big one) got to pet a tiger shark. Ocean World is much smaller than the Oregon Coast Aquarium, but we loved it. You have a tour guide who leads you through the exhibits, teaching about the different fish and animals, including stories about where each animal was found.
After so much time spent reading informational posts, the boys were more than happy to let someone else handle the learning bits.
One of the highlights for them was getting to touch a leopard shark. For me, it was later when they told the waitress at dinner how shark skin was once used for sandpaper, and that in one direction sharks feel like felt but in the other direction like sandpaper.
The other peak of the excursion was the sea lion. She did all kinds of things -- catching rings, doing sommersalts, going down a slide, jumping...the boys were mesmerised. I think they would have watched the entire show again if Grace would have stood for it.