Perhaps this isn't your thing. Perhaps you'll hate it. But I think as much as you love nature and animals I think you will really enjoy Discovery Cove.

I signed us up for a Dolphin Encounter. Basically we'll get into water with a trainer and a dolphin to interact for about 20-30min. Rest of the time we can do whatever we want. We can go swim and snorkel in the man-made reef. It's absolutely lovely. Water is crystal clear. It's fairly shallow and all you see is beautiful school of fish.

Basically all the beauty without any worry about sharks or any other dangers.

They also have few other animal things around the park -- but we can play it all by ear and see how the day goes. We have private seating area reserved so we should be secluded from people. Also, these are cool months of the year so we shouldn't be dying from heat exhaustion :)  I am hoping this will also ensure that it isn't too corwded.