The coral is as interesting as the fish

Don't just look for things that move.

The bay contains sea fans, sea rods, brain coral and branching corals. Look closely and you begin to understand that the reef itself is alive.

One of my favourites is the Christmas tree worm. Look for tiny red, blue, orange or white spirals sticking out of the coral. Move your hand gently through the water nearby without touching anything and they can disappear instantly into their tubes.

Sea urchins are usually tucked into holes and crevices. They are an important part of the reef because they graze on algae that would otherwise compete with coral. They are endangered in the Caribbean so no eating please.

You will also see underwater grasses and algae, including turtle grass, manatee grass, Mermaid's fan, sea lettuce and Halimeda. Halimeda is particularly interesting because it contains calcium carbonate. When it dies and breaks apart, its fragments eventually become part of the beautiful white Caribbean sand.

Anything that can hurt you?

Almost nothing in the bay wants anything to do with you. Problems generally happen when people touch something, stand on the reef, put their hands into holes or bother an animal.

• Fire coral is probably the thing a snorkeler should be most careful about. It can give you a painful burning sting. Don't touch it.

• Sea urchins have extremely sharp spines. Never stand on the reef and don't put your hands into crevices.

• Stingrays are peaceful animals, but they have a defensive spine on their tail. Never step on, chase or corner one. Give it room.

• Moray eels have powerful jaws. They are not hunting snorkelers, but never put your hand into a hole in the reef and never try to feed or touch one.

• Barracuda deserve respect. Don't feed them or chase them. If you see one, simply keep your distance and watch.

• Nurse sharks are generally calm around people, but they are still wild sharks. Never touch, feed, chase or corner one.

• Porcupinefish and puffers are not dangerous to watch. Don't touch them and never try to make one inflate.

• Needlefish are not normally aggressive, but they are fast fish with very pointed jaws. Leave them alone, particularly when they are close to the surface.

The most important rule is simple: Look at everything. Touch nothing.

A few Cliff Villa snorkeling rules

• Always snorkel with someone else. Never snorkel alone.

• Stay inside the bay. Do not swim out into the open ocean. There can be a strong undercurrent beyond the protected area.

• Never jump from the top of the cliff.

• Do not stand on the coral, break coral or remove shells, fish, coral or anything else from the water.

• And don't rush. You can snorkel the same small area every day for a week and see something different every time. That is part of what makes the bay below Cliff Villa so incredible.