Sipadan claims to be the world's best dive site. While this is a big claim, the diving here is certainly world class. Sipadan used to have resorts but to protect the environment these were closed around the year 2002. To dive on Sipadan you have to stay somewhere nearby, such as on Mabul or in Semporna, and take a boat onto the island.
Because Sipadan is now a protected site, only 120 dives are allowed daily (as of 8/26/08). It's best to try to dive as early as possible to beat the crowds and increase your chances of getting on the roster to dive.
From the main beach of the original resort it is a mere 20m wade over the reef to reach the top of the reef wall dropping 1000-2000m. Sipadan is surrounded by very rich reef life consisting of both hard and soft coral as well as all manner of reef fish. Sea turtles and white tip reef sharks can be seen on almost every dive and hammerhead and leopard sharks can also be seen at times. Visibility ranges from 10m to 30m and above.