Private Snorkeling at CSA

I read on a couple of post somewhere that you can book a private snorkeling excursion where they take you out for a few hours to several different sights. I believe I read that lunch/snacks were included. Does anyone know if this is available, the price, if reservation are required and most importantly is it worth it.my husband and I are traveling to CSA for our second time in December and thought a private excursion would be fun. Hopefully some fellow CSA member can provide us with some feedback.