Blue Lagoon is a narrow cove with coral and fish close to shore. The sides of the cove are sharp volcanic rock. There is a small white sand beach, which nearly disappears at high tide. On the high ground above the beach are two small restaurants where you can eat and drink, sit on deck chairs, hire snorkel gear and shower.
The best and least damaging way to get into the water is from the northern side of the beach where a small channel between the rocks leads to deeper water. Elsewhere along the beach the water is fairly shallow and entering here can lead to cuts as well as damage the coral.
Warning: currents can be strong on the outer edge of the cove and an incoming tide can bring stingers and rubbish.