Difference between revisions of "Diving the Cape Peninsula and False Bay/Di's Cracks"
Revision as of 10:49, 27 December 2011
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.
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). A permit is required.
The site is named "Di's Cracks" for the deep cracks between the huge granite outcrops, which are wide enough to dive, and Di Froude, a local diver who discovered and popularised the site.
Maximum depth is over 30m. Average about 18 to 20m. Top of pinnacles about 10m.
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.
There are several swimthroughs right under and among the jumble of huge bolders which form one of the pinnacles at about S34°03.858’ E018°18.393’. The pinnacle is generally about 12m deep but there is a small area at the south end which comes up to about 9m and the bottom in this area is about 30m. Several of these swimthroughs are fairly spacious.
Geology: Granite of the late Pre-Cambrian Peninsula pluton
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.
I surface current may be experienced, (This has been measured on one occasion at about 1km/h setting about 170° magnetic, in light south easterly wind)
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.
The site is only accessible by boat. It is about 5.7km from Hout Bay Harbour.
Heavy encrustation of invertebrates on the rocks, particularly on vertical and overhanging faces.
The cracks: Deep, almost vertical walled gaps between the outcrops, and swimthroughs.
A good site for macro and wide angle photography.
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.
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.
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 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. 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.