Portions taken from www.CaveBiology.com Stargate Blue Hole is located about 500 m inland from the east coast of South Andros Island on the west side of The Bluff village. It is part of a major north-south slump fracture zone paralleling the underwater escarpment that separates the Great Bahama Bank from the Tongue of the Ocean, a deep oceanic trench. This slump fracture extends for tens of kilometers and was formed as a result of glacio-eustatic sea level changes and gravitational stresses along the edge of the limestone banks (Palmer, 1986a & b).
The entrance to this cave is a partially roofed-over cavern with a vertical drop of 6 m to water level. The restricted nature of the entrance limits organic input and as such, the surface water is relatively clear. Underwater, a shaft drops vertically to depths in excess of 80 m, while rift-like passages extend north and south. To the north, a 10 m wide passage with the roof at -20 m depth extends for 107 m to a breakdown choke. To the south, a similar passage runs for 100 m to another choke, passable on the right hand side at -37 m to reach an extremely loose boulder chamber that chokes again after a further 30 m.