Diving at SURG Pinnacles
The dive site SURG Pinnacles is an offshore rocky reef in the Duiker Point area on the west coast of the Cape Peninsula, near Cape Town in the Western Cape province of South Africa.
Understand[edit]
This site is a fairly compact group of large pinnacles which is deeper than most of the nearby dive sites, while still shallow enough for recreational divers. The greater depth makes it a bit safer for the boat in relatively strong swells, though the surge can be quite strong.
Position[edit]
- 1 Southern pinnacles: S34°02.375' E018°18.015' — (Shallowest of southern pinnacles)
- 2 Northern pinnacles: S34°02.348' E018°18.018' — (Centre of northern group)
The shallowest of the southern pinnacles is a short distance offshore from the large reef with several shallow pinnacles and an exposed rock, which includes Kanobi's Wall to the north and Star Walls to the south.
This site is in the Table Mountain National Park Marine Protected Area since 2004. A permit is required. The site is within the Karbonkelberg restricted area, where abalone and lobster poaching is prevalent. Poachers operate from Hout Bay harbour in broad daylight, and appear to be avoided by the police and government authorities tasked with conservation in this area.
Name[edit]
The name "SURG Pinnacles" was given in commemoration of the very strong surge on the day the site was first surveyed, and the local organization SURG (Southern Underwater Research Group) which contributed towards the mapping of the site.
Depth[edit]
Maximum depth is more than 30 m, and the top of the shallowest southern pinnacle is about 9 m. (Average depth of a dive is likely to be about 20 m.)
Visibility[edit]
Visibility is variable, as with all sites in the region. On a really good day it may exceed 20 m, and will then usually be very cold. These conditions normally occur in summer, when upwellings driven by the strong south easterly winds bring cold, clear, deep water to the surface. The good visibility does not often last long, and is usually followed by a plankton bloom soon after the wind dies down. More often the visibility is less than 10 m, and it is quite commonly around 5 to 8 m in ordinary diving conditions. Of course it can easily be worse, and may be as low as 3 or 4 m, even if the conditions otherwise look good. This means that you just have to look closely at the critters, and for this a light is useful. In low visibility it will be more difficult to navigate around this moderately complex area.
Topography[edit]
The site includes two clusters of pinnacles which are fairly close to each other, the southern group forms a ridge running roughly west to east, as does the larger northern group. Together these groups form a larger scale ridge running north to south.
This whole area of pinnacles and ridges to the west can be considered part of the Star Wall/Kanobi's Wall reef, which is a contiguous area of moderate to high profile granite outcrops and boulders covering a fairly large area, as shown on the map, with several shallow pinnacle tops not shown on the official charts of the area. Many of these are shallow enough to be a navigational hazard to small craft if the tide is low or the swell is big. The large exposed rock at Kanobi's Wall is shown in the wrong place on the SAN charts.
Geology: Granite corestones of the late Pre-Cambrian Peninsula pluton.
Conditions[edit]
Surge — The site is exposed to swells with a westerly component, which can produce a strong surge over the top of the pinnacles and in the gaps. Surge is usually weaker in deeper areas.
Currents — At times there is a slight current, usually caused by the wind. The main strength of the current is usually at the surface and down on the reef it is usually much weaker. Surface current may exceed 1 knot, and may occur even if the wind is not strong.
Temperature — The water will usually be cold. Temperatures are generally 12°C or less, but have not been recorded lower than 8°C. 14°C would be considered unusually warm. A thermocline of one or two degrees may occur, and this is often associated with a change in visibility.
Seasonal variations — Conditions suitable for diving this site will be most common in summer, but any time when the south westerly swell is weak and low may be suitable, though visibility may be more unpredictable in winter.
Upwellings and plankton blooms — This is an area which sometimes has upwellings, caused by the south easterly wind, which generally bring in cold, clear, nutrient rich bottom water. This will usually develop a plankton bloom over a day or two of good sunshine, which will reduce shallow water visibility again. This means that the best times to dive are during or directly after an extended period of moderate to strong south easterly winds, and this generally happens in summer. A plankton bloom which reduces surface visibility to 2 to 5 m may well only extend down a moderate distance, and the visibility below will usually be better. The depth of the bloom is unpredictable and may range from around 5 or 6 m to about 20 m. Light levels below the bloom are often drastically reduced, and the colour tends to be very green.
Get in[edit]
The site can only be accessed by boat. It is about 6.6 km from the slipway at Hout Bay harbour. The ride will usually take 10 to 20 minutes, depending on the weather. It there is a strong south easterly wind, the ride back will be relatively wet and bumpy. It is usual to fully dress in your wet or dry suit before leaving the harbour, though gloves and hoods may be left until you reach the site. Completion of kitting up and pre-dive checks are done on site. This site may be diveable when the swell is too high for safety at shallower sites nearby, as there is less of a problem with breaking seas over the reef, which may make it difficult to pick up divers at the other sites.
See[edit]
Marine life[edit]
Typical of the big reefs of the Atlantic coast. Moderate growth of red bait and split-fan kelp on top. Walls, crevices and overhangs are covered with a large variety of sponges, corals, ascidians and other sessile invertebrates, and a host of small mobile critters, many of them well camouflaged.
There is a marked difference between the benthic ecology on the more vertical parts of the reef and the flatter areas. The walls and slight overhangs in the 12 to 24 m range probably have the most diverse invertebrate cover, and certainly the most colourful. There are large numbers of small gorgonian sea fans, noble corals, soft corals, hydroids, anemones, sponges, colonial ascidians, and bryozoans, providing shelter and food for more mobile invertebrates, The predominant colours are oranges and browns.
A very high population of hairy brittle stars and immature cape urchins was recorded in November 2013
-
Sponges at 18m depth -
Yellow sponge and red klipfish -
Starfish, urchins and mussels -
Fanworm and starfish -
Whelks -
Starfish, brittle stars and urchins at 18 m depth -
Sea anemone and sea squirt -
Strawberry anemones and sponges -
Red bait pod -
Juvenile West coast rock lobsters
Features[edit]
This site has very high profile reef, with a large proportion of near vertical to overhanging rock faces, and several deep, narrow gaps between the rocks. There are also some swim-throughs, though the positions are not recorded. The site is spectacular when the visibility is good enough to appreciate the topography.
Photography[edit]
This is a good site for invertebrate photography. Most of the subjects will be less than 250 mm long, and there may be some much smaller, with a large variety in the 20 to 100 mm size range.
If the visibility is good, there may be opportunities for some fairly spectacular scenic shots, with or without divers, and you may be visited by a seal.
Macro and wide-angle equipment are most suitable, and super-macro may also be appropriate. The reef is colourful, particularly in the 15 to 25 m depth range, where the most of the red and orange light will already have been absorbed by the water, so good artificial illumination is recommended to get the most out of wide angle shots.
Suggested Routes[edit]
No routes are known yet. Start deep and work your way up. Decompression or safety stops will have to be in mid-water or on the shotline as there is no shallow reef nearby.
Stay safe[edit]
Hazards[edit]
The site is in a very exposed area and one should not dive there if there is big swell or strong wind. Skippers beware of the nearby pinnacles of the Star Walls Reef Complex on the route to and from the site, as not all are mapped, and some of them may break unexpectedly if there is big swell or a low tide. This is a particular problem when the swells are in "sets", as there may be a long period where the swells are low and well behaved, followed by a few big ones, which can lift and break without much warning, and can be quite stressful if the boat is over the top of the reef at the time. It is prudent to go around the main reef, rather than over it. The route north of Kanobi's Wall is relatively clear of pinnacles which may break.
The pinnacles are moderately sized and not particularly easy to find. A shotline is recommended to help divers find the pinnacle, and may be useful for controlling ascent, but this will depend on swell and current. It is relatively safe to ascend on a DSMB, as the current will generally not carry divers toward the shallow areas and breaking seas.
Other hazards are cold water and strong surge, especially around the pinnacle. Strong offshore winds may develop over a short time in summer, but these are usually forecast.
Skills[edit]
It is possible to restrict oneself to depths above 18 m if one's buoyancy control is good, but most boat operators will probably insist on certification for at least 30 m, as much of the site is between 18 and 30 m.
Ability to deploy a DSMB from mid-water is strongly recommended, good buoyancy control is essential.
Equipment[edit]
A DSMB is useful if you surface away from the shot line or there is no shot line. Diving with a standard SMB is not recommended unless you have a really good reason and are adequately skilled to avoid snagging the line on the steep sides and overhangs.
Nitrox can significantly extend your dive time if you are well insulated, and a dry suit is recommended as the water will be cold. If you have a full face mask, it will help on the really cold days, but most divers just allow a few minutes for their face to get used to the cold.
A dive light is worth taking along, as if the surface water is turbid or the lighting is just gloomy due to depth, it may be fairly dark in the deeper areas, and artificial lighting will bring out the bright reds, oranges and yellows of the invertebrates on the face of the walls and under the overhangs and swim-throughs. A wide angle light beam is best, as it allows close up examination of the organisms while illuminating enough of the surface that you don't have a tiny hot spot on a generally dim background.
Nearby[edit]
- 1 Die Middelmas
- 2 Twin Towers
- 3 MV Ker Yar Vor and the Jo May
- 4 SS Maori
- 5 SAS Gelderland
- 6 SS Oakburn / MV Bos 400
- 7 Die Perd
- 8 Kanobi's Wall
- 9 SURG Pinnacles
- 10 Star Wall
- 11 Sunfish Pinnacle
- 12 Canyon
- 13 Stonehenge Dusky Pinnacles - Coral Pinnacle
- 14 Stonehenge Blinder
Back to the Alphabetical list of sites, or list of dive sites in the Outer Hout Bay area
Other regional dive sites: