So I asked earlier about making reservations ahead of time. Many said no. However, would I have to make a reservation for snorkeling for a group of 10 or less? Does anyone know? And where do I make the reservation?

Snorkeling boats, glass bottom boat, visitor centwr/aquarium, and dive boats are all fully operational. Food Concession and gift shop are scheduled to open in the rebuilt building next week. (as of 2/27/18)

There is no need to make reservation for snorkeling. However it is simple, call the park or visit homepage and you can clear your concerns

They are recovering from a hurricane and so most of the concessions are not operating or at least not fully operational

I think you can make a reservation online