High Quality Content by WIKIPEDIA articles! Palancar Reef is a large coral reef located on the southwest side of the island of Cozumel and is part of the Arrecifes de Cozumel National Park. The site is very popular with scuba divers and is divided into several sections based on depth coral formations. Dive depths range from 50 to 110 feet, with coral swim-throughs located in many places.