You CAN NOT miss stingray city in Grand Cayman, it is incredible!!!
We've gone with a few operators there and I recommend the one of the following for your group.
My first would be to suggest a private sailing charter to stingray city, you can charter a sailboat called the
yep, the name says it all, relaxing
. Is $350 including everything !!! The Captain was amazing, really nice and helpful.
The other option would be Snorkelers Dream Catamaran
another great trip but its a bigger catamaran an they take more people but is only $34 for adults and $20 for kids.