There are a TON of things for the kids to do in the Caymans. Google the island and you'll see all of the things geared toward kids. It's been 20 years since I was there with my 4 kids and we all had a blast.
I am travelling to the Cayman Islands along with my family later this month, I want my kids to enjoy the most, what activities are there for kids?
Nice to see you want your kids to enjoy the most out of your trip. There are many outdoor activities that you can indulge in along with your family. There are some beaches where kids specific sports are held every day. Make yourself the priority also, do visit Underwater submarines with your kids. They even offer the ride at night so as you can experience both the daytime underwater world. Go for scuba diving as well while your kids play with Sandcastle :P