Difference between revisions of "Diving the Cape Peninsula and False Bay/Justins Caves"
Revision as of 08:30, 31 August 2009
The Dive site Justin's Caves is an extensive area of rocky reef in the Oudekraal area on the Atantic 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.
The site has spectacular topography and colourful ecology, and is justly one of the more popular shore dives of Cape Town.
Name "Justin's Caves"
There are a number of small caves and spacious swimthroughs which contribute to the name, but it is not recorded who Justin was.
S33°58.848’ E018°21.473’ (Shoreward entrance to main cave)
S34°58.85’ E018°21.50’ (The highest rock in the group)
The southern group of rocks off the point at North Oudekraal
This site is in a Marine Protected Area (2009)
Shore dive. Parking at the side of the road on outside of bend north of the Twelve Apostles Hotel near S33°58.941’ E018°21.594’. There is an entry/exit point directly opposite the caves at the bottom of a slope covered with rounded boulders of medium to small size at S33°58.910’ E018°21.571’. This gives the most direct route to the caves which are under the group of large granite boulders about 150m offshore. The gully is quite shallow over rounded sandstone boulders and there is a nice flat granite rock at the entry point to put gear on if the tide is low enough. If the tide is very low the kelp can be a bit of an obstacle, particularly in the gully, and the rocks can be slippery. An alternative entry and exit point which is far more protected from the South West swell is at Sandy Cove, about 50m to the north, but if the conditions are too rough at the entry described here, the caves will be very surgey.
The site is not generally done as a boat dive, but if it is, the boat should stay out of the channel between the rocks and the shore, as unmarked divers use this area on the surface and at shallow depth, and there is a dense kelp forest. The ground is generally unsuitable for anchoring, and boats should not be left unattended at anchor.
There are no facilities provided. Security is no better than at any other roadside parking in the area.
The site is often at it's best during or after south easterly winds, but strong south easterly winds (offshore) can make it difficult to swim back to shore at the surface. It is exposed to south westerly swells, and surge can be strong, particularly in the swimthroughs.
The site is usually at it's best in summer, but there are also occasional opportunities in autumn and early winter.
This is an area which sometimes has upwellings, caused by south easterly winds, resulting inclear cold water, which may develop an algal bloom after a few days, which will reduce the visibility.
Keep a lookout for times when the south west swell is low and short period, and the south easterly winds have just stopped, for a good probability of good diving conditions.
The bottom is generally from about 8m about to 13m. There is very little sand.
Corestone boulders and outcrops of late Pre-Cambrian granite of the Peninsula pluton.
Big granite corestone boulders with several swim-throughs, narrow gaps, walls, overhangs and caves. Hardly any sand bottom visible between rocks. Spectacular in good visibility. There is a large iron anchor thought to be from the wreck of Het Huis te Kraaiestein on the low granite outcrops north of the caves.
Cold water, Hot sunshine. Strong surge in gulleys and swim-throughs. Sea urchins. Strong offshore winds may develop over a short time (check the forecast). Dense kelp forests en route for shore dives (can be tiring to swin through at the surface). Rugged and slippery rocky access route.
No special skills required. Reasonable fitness and agility are recommended due to the clamber over slippery rocks at the entry and the moderately long swim out to the site and back. The swimthroughs are reasonably spacious, but are an overhead environment for several metres, and the surge inside may be quite strong. One of the swimthroughs involves a significant change of depth.
A good site for macro photography, and wide angle work if the visibility is good.
A light is recommended for looking into caves and overhangs, and because of the loss of colour at depth. A compass is recommended and the return should be done underwater if the wind picks up during the dive. Do not tow a SMB here unless you have a really good reason, as it will hook on kelp and keep you out of the caves.
There is a large and fairly dense kelp forest on the way out and back, which can be a bit of an obstacle on the surface at low tide. The rocks at the caves are covered in the typical reef life of the area, with spectacular growths of sponges, soft and noble corals, sea fans and ascidians in the sheltered areas under overhangs and in the swimthroughs.
Swim out on the surface to the highest rock in the group. Dive and follow the high rocks generally south. Go through the swim-through at approximately S33°58.863 E018°21.475 then head north to the main swimthrough at S33°58.848’ E018°21.473’. Fom the far side of this swim north again some 40m over fairly flat granite outcrops and see if you can find the anchor at S33°58.825’ E018°21.444’. Return to the main group of rocks and spend your remaining time exploring the various gaps and overhangs among the boulders. Return to shore at shallow depth on a compass course of about 150° magnetic to avoid wind and kelp fronds. Exit at same point as entry.
Views of the site from the shore.
View of the site from the entry and exit point which is in the middle foreground of this photo. The caves are under the group of granite boulders in the background. The first swimthrough referred to in Route 1 is under the second high rock from the left, and the main swimthrough is under the low rock just to the right of that in the photo. Access is over the small round boulders in the foreground and through a gap to the left of the gully. Swim out on the surface to just short of the high rock in the background. The gully is quite shallow and at low tide the kelp is a hassle.