Diving the Cape Peninsula and False Bay/Stonehenge
The dive site Stonehenge is an offshore rocky reef in the Karbonkelberg headland area on the Atlantic seaboard of the Cape Peninsula, near Cape Town in the Western Cape province of South Africa.
It is a good site for varied topography, biodiversity and depth variation.
The site is only accessible by boat. It is about 6.5km from Hout Bay harbour.
S34°02.838’ E018°18.316’ (Top of blinder)
South of Duiker Point, below Karbonkelberg
This site is in a Marine Protected Area (2009). A permit is not required.
The area is named "Stonehenge" after a more or less circular ring of rocks which break the surface near a much larger rock which is shown on the charts.
Maximum depth is over 22m, with an average of about 12m to 15m
Big boulders and rock outcrops over an extensive area. High relief in deeper areas with swim-throughs, holes and overhangs.
Stonehenge blinder is a huge granite corestone pinnacle about 65m E-W by 45m N-S at base, tapering to 45m E-W by 25m N-S near the top. There is a narrow crack about 1.5m wide and several metres deep by 15 or more metres long near the south east side, and the north side is very sheer. The top point is a bit away from the north eastern edge and is about 3m deep. The bottom is rock at 20m+.
Geology: Granite of the late Pre-Cambrian Peninsula pluton
The site is exposed to south westerly swells, so best when the south west swell component is low and short. This may occur after south easterly winds. The site is usually at it's best in summer, but there may also be occasional opportunities in autumn or early winter.
This is an area which sometimes has upwellings, caused by strong south easterly winds, resulting in cold clear water, and may then have a plankton bloom, which will reduce the visibility again.
Typical of the big reefs of the Atlantic coast. There is a heavy growth of red bait in shallow areas, Kelp on top surfaces in moderate depths, and fairly bare rock with urchins on relatively flat deep surfaces. Walls, overhangs and other steep surfaces are covered with wide variety of sponges, corals, ascidians and other invertebrates.
Good photographic site. (photographic equipment suggestions)
Drop in at the pinnacle and descend to the bottom. Slowly ascend as you swim around the pinnacle, observing the various zones. If the sea is calm, a safety stop can be done over the top of the pinnacle.
Cold water, Strong surge in gulleys and swim-throughs, and over the top of the shallow parts of the reef. Strong offshore winds may develop over a short time.
No special skills required. The ability to deploy a DSM and use a compass is useful.
A light can be useful to look into dark places and to restore colour at depth. A compass can help keep track of your position, and a DSMB is handy to allow the boat to keep track of ascending divers. Nitrox can extend your no-decompression time if you are well insulated.