Difference between revisions of "Diving the Cape Peninsula and False Bay/Tafelberg Deep"
Latest revision as of 09:28, 21 November 2011
This site is not well explored, and is used mostly for divers who want a dive in the 40 to 50m depth range which can be ended in shallower water.
This is the extreme southern end of the known reef in the Tafelberg Reef area and is the southern edge of the south-easternmost part of the reef complex extending south from the Karbonkelberg. This is an area of relatively steeply shelving reef, as the average slope from the reef edge to the pinnacle is about 1 in 5. It is about 500m south west of the pinnacle at Klein Tafelberg Reef
This site is in a Marine Protected Area (2004). A permit is required.
The name "Tafelberg Deep" refers to the adjacent Tafelberg and Klein Tafelberg reefs, and that the depth is greater. The Tafelberg Deep Pinnacle is the nearest pinnacle to Tafelberg Deep.
Maximum depth is about 50m at the edge of the reef, and the top of the pinnacle is about 18m. It is about 190m from Wilhelm's mark to the pinnacle, on an upward slope of about 1 in 5 average gradient. It should be quite easy to navigate as the direction is about 355°magnetic, which is almost directly North.
Tafelberg Deep Pinnacle: — A huge outcrop of granite with a cluster of pinnacles. Very steep profile at and near the top, flattening out below about 24m to the south.
The fist sand patches between rocks have been found at 41m to the south.
Moderately to steeply sloping slope of granite boulders and outcrops to the south. There is a ridge several metres high interrupting the slope to the south.
Tafelberg Deep: — The sand edge runs roughly east-west for about 200m and is very close to the 50m contour.
Geology: Pre-Cambrian granite of the Peninsula pluton. Sand at the bottom to the south.
The site is exposed to south westerly swells, which can cause a surge. The site is usually at it's best in summer but there are also occasional opportunities in autumn and winter. Short swells will often not affect the bottom conditions due to the depth.
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.
The site is only accessible by boat. It is about 5.3km from Hout Bay Harbour.
The reef life tends to have more sponges due to the depth, otherwise similar to other reefs in the area. The seldom seen Gilchrist's sea urchin has been recorded from this site.
The site is mostly quite deep and often quite dark. Natural light will not be sufficient most places and times, and be sure that your camera housing is rated to the depth. Macro equipment is most likely to produce useful results, particularly in the deeper areas.
The recommended procedure is for the skipper to find the desired depth using echo sounder and GPS, and put down a shotline. Divers descend on this and swim a compass course toward the Tafelberg Deep pinnacle, on a bearing calculated by the skipper from the GPS positions of the two points. However, it is possible for divers to run out of planned bottom time before reaching the pinnacle, in which case they should deploy a DSMB and surface on that.
Nitrogen narcosis, decompression sickness, Cold water.
Certification and skills for diving to 50m and using the appropriate equipment.
Compass and DSMB with reel or spool are necessary due to the nature of the dive. Trimix and deco gas strongly recommended. Dry suit and light recommended.