I can't say enough good things about the Blue Grotto. The people running the operation are kind and will go out of their way to make sure you have a good time. The facilities are fantastic and as long as you go after 3pm (once the classes wrap up), you'll have the place all to yourself. The grotto only allows snorkelers under the condition that they are accompanied by divers and that does a great job at keeping drunk college kids away (unlike Devil's Den down the road). We tent camped for 3 nights and dove during the day on our own.