Sinkhole
Boesmansgat
The single entrance to the Boesmansgat sinkhole on a private game farm in the Northern Cape: a narrow crack leading to a vast, very deep flooded chamber used for record-depth expeditions.
The dive entrance to Boesmansgat is a small crack, roughly 1.5 m by 3 m, at the bottom of a steep scramble on Mount Carmel game farm. Below it the flooded chamber widens rapidly into a very large void that continues to a silty floor at roughly 282-286 m.
Diving here is expedition work. A 2002 team needed about five hours just to move its equipment to the water's edge, and reported the nearest recompression chamber as about seven hours away. The documented dives are deep, long and supported by large teams, and the site is on private land with no public access procedure.
The environment
Clear, still fresh water of about 19 C (1996 and 2002 reports) in a huge dark chamber; brown mud on the walls absorbs light, and the bottom is fine silt that clouds easily. At about 1,500 m altitude, decompression has to be adjusted for the lower air pressure.
Conditions
Temperature figures are from 1996 and 2002. The water level has changed over time.
Typical ranges from published sources, not current conditions.
Facilities
No dive facilities are documented; a 2002 team described a steep scramble to the water, a five-hour equipment carry and a recompression chamber about seven hours away.
For orientation, not navigation. Hollow dots are approximate.
Every fact on this page, with its source (8)
| Fact | Status | Source |
|---|---|---|
| Boesmansgat is on Mount Carmel, a game farm near the Kuruman-Danielskuil road, about a 30-minute drive from the farmhouse. | Reported | [1] [2] |
| Area-level coordinates only; the entrance is on private land.Rounded to 0.1 degree on purpose. | Reported | [3] [1] |
| The deepest point reached is 282.6 m (Gomes, 1996).283.3 m (Mail & Guardian 1996) and 286 m (GUE 2002) are also published. | Sources conflict | [4] [5] |
| A 2002 GUE team worked at depths between 30 m and 90 m in the upper chamber. | May be out of date | [1] |
| About 19 C in 1996 and 2002. | May be out of date | [4] [1] |
| Divers drop through a crack about 1.5 m by 3 m; the chamber opens quickly below, with brown mud on the walls and silt on the floor. | Reported | [1] [5] |
| The sinkhole is on a private game farm; no public procedure, fee or opening hours were found. | Reported | [1] [2] |
| The descent to the water is a steep scramble and moving dive equipment to the water's edge took about five hours in 2002; the nearest recompression chamber was then about seven hours away. | May be out of date | [1] |
Verified: stated by an official or primary source we opened. Reported: from a secondary source only. Sources conflict: the note gives both versions. May be out of date: the newest source we found is old.
Written in our own words from the sources above. Report a correction