Muck diving gets its name from the sediment that lies at the bottom of many dive sites - a frequently muddy or "mucky" environment. Other than muddy sediment, the muck dive substrate may consist of dead coral skeletons, discarded fishing equipment, tires and other man-made garbage. In addition, the visibility is usually less than on the reef or wreck sites of the area.
Why people muck dive
The "muck" substrate can be the habitat for unusual, exotic and juvenile organisms that make their homes in the sediment and "trash" that compose a muck dive. The sediment and detritus environment has a different ecology to the reef. Creatures like colorful nudibranchs, anglerfish, shrimp, blue-ringed octopus, and rare pygmy seahorses may be more common, more easily found, or restricted to a sedimentary substrate.
Where people muck dive
The most popular region for muck diving is Southeast Asia, where there are more marine species than anywhere else in the world. Places like Mabul and Kapalai in Sabah, Malaysia, Anilao and Dauin in the Philippines, Lembeh Straits in Manado, Indonesia and Bali are popular because of the different creatures found in this type of bottom ecology.
Other sedimentary bottom habitats may also provide interesting ecologies, and muck diving is possible almost anywhere that recreational diving is possible.