Very cool tour. I booked with Coral Breeze limited, I was worried cause It wasn't offered with the ship. Im so glad I booked this tour. First of all there are less people then the herd you get with the ship so that is a plus. Second this company is owned by Americans. They answered any questions promptly by e mail. The staff was very friendly and helpful. Very professional. We saw tons of sting rays and a nurse shark. Then snorkled the reef and saw colorful fish.The water is warm and clear. Lunch was on lovely Caye Caulker. A laid back pretty little island. It was easy to find our tour guides they held signs and are right in the area the ships tenders let us of at in the tourism village. The price is also good. I would book with this company again.
I can answer your first two questions. You are in pretty shallow water. I am 5'3" and if I stood on my tip-toes, I could reach the bottom. The sting rays come fairly close. They seem closer than they are. I kept trying to touch one but they never came that close to me. However, sometimes they did brush past my legs. It sounds scary but it's really not. Hope this helps. Have fun.