Study the different species of fish and wildlife in the snorkeling area. Guide books give you an idea of what you might see beforehand.
Buy a proper fitting mask and snorkel before your snorkeling excursion. Place the mask on your face without the straps and see that it makes a proper seal. Then put the straps on and adjust them to see if the mask is comfortable. Buy a mask that has straps that are easy to adjust. This is especially important if other people will be using the same gear.
Check that the snorkel properly fits in your mouth and that it is easy to bite down on the mouth piece.
Buy a rash guard if your skin burns easily. It is best not to use sunscreen lotions, which can be toxic to many aquatic species.
Keep your hands to yourself when snorkeling. Do not touch the reef or any animals. The reason for doing this is to protect yourself and the organisms from any injuries. You can get scraped when touching coral, which is laden with bacteria and can cause infection.
Use a flotation device if you are not a strong swimmer. Stay in areas that are not too deep.
Do not stand on rocks or coral to prevent damaging the coral and killing sea life that live on the rocks or on the reef. Only stand in sandy areas.
Do not stir up the bottom because the sand or silt can settle on and suffocate the corals or other species. When you want to move, gently push off from the bottom. When you are a few feet above the sand, kick your fins using a straight-legged motion.
Promote a safe environment for aquatic life by preventing pollution on land. The pollution that comes from the shore or from rivers brings pollution from the inland and threatens coral reefs and the organisms that live there. Pack up all of your trash.