Diving the Cape Peninsula and False Bay/Di's Cracks
The dive site Di's Cracks is a reef in the outer Hout Bay area on the Atlantic seaboard of the Cape Peninsula, near Cape Town in the Western Cape province of South Africa. Information is provided which may assist in planning Recreational and Research Scuba diving at this site, and links to photographs of marine organisms that have been found there.
A spectacular dive if the visibility is good. Lots of walls and overhangs, swimthoughs and deep, wide cracks between enormous granite outcrops. The walls are heavily encrusted with marine organisms.
Name "Di's Cracks"
The site is named for the deep cracks between the outcrops, which are wide enough to dive, and Di Froude, a local diver who popularised the site.
S34° 03.875’ E018° 18.414’ (Pinnacle 1)
S34° 03.868’ E018° 18.399’ (Pinnacle 2)
S34° 03.878’ E018° 18.421’ (Arch swim-through)
About 300m north west (328° magnetic) of Vulcan Rock
This site is in a Marine Protected Area (2009)
The site is only accessible by boat. It is about 5.7km from Hout Bay Harbour.
The site is exposed to south westerly swells, which can cause a strong surge. The site is usually at it's best in summer but there are also occasional opportunities in autumn and winter.
This is an area which sometimes has upwellings, caused by strong south easterly winds, resulting in cold clear water, which may develop a plankton bloom over a few days, which will reduce the visibility again.
Keep a lookout for times when the south west swell is low and short period, and there is not too much south easterly wind forecast.
Maximum depth is over 30m. Average about 18 to 20m. Top of pinnacles about 10m.
Granite of the late Pre-Cambrian Peninsula pluton
Big granite outcrops and boulders with overhangs, a few swim-throughs, and the cracks, which are deep and wide enough for a skilled diver to keep clear of the sides.
Cold water, Strong surge in cracks and swim-throughs. Sea urchins. Strong offshore winds may develop over a short time, making it tricky to spot divers on the surface, and a wet trip back.
Good buoyancy control, trim, and finning technique is necessary to avoid damaging the encrusting organisms on the walls.
A good site for macro and wide angle photography.
The site is cold and relatively deep, and a dry suit is recommended. This is a dive site where the use of Nitrox can be worthwhile to extend no-stop time. A DSMB is recommended for the ascent and for individual divers in case of seperation from the group, even if only to signal to the boat when on the surface.
Heavy encrustation of invertebrates on the rocks, particularly on vertical and overhanging faces.
Most suitable as a live-boat dive as this allows the divers to explore the area without having to find their way back to the boat. A surface marker buoy may be useful to show position of the group, but hinders access to overhangs and swim-throughs, and may snag on red bait at top of walls.