It gets its name from the sediment that lies on the bottom at many dive sites - a frequently muddy or "mucky" environment.
Other than muddy sediment, the muck dive substrate may consist of dead coral skeletons, garbage and natural detritus.
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.
[3] The most publicised 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,[4][1] Indonesia and Bali are popular because of the different creatures found in this type of bottom ecology.