Whittle Rock and the surrounding reefs cover a large area, and are the most significant navigational hazard in False Bay, but as very little shipping of large displacement enters the bay, it is not at present that much of a problem. The Euphrates is reported to have been wrecked on the reef, but its position is not known. Several anchors have been found, and some of them mapped. It is also a popular fishing area for reef fish, and a spectacular dive site. It would certainly be more popular if it was closer to the launch areas.
- S34°14.846' E018°33.714' 1 Whittle Rock (Shallowest pinnacle): About 8 km offshore
- S34°14.887' E018°33.775' 2 Whittle Rock South-east Pinnacle
- S34°14.844' E018°33.682' 3 Whittle Rock West Pinnacle
- S34°14.765', E18°33.622' 4 Whittle Rock North-west Pinnacle
- S34°14.783' E18°33.795' and S34°14.776' E18°33.801' 5 Euphrates anchors
- S34°14.756' E18°33.720' 6 JJ's anchor
- S34°14.735' E18°33.590' 7 Riaan and Sven's anchor
- S34°14.762' E18°33.575' 8 September anchor
- S34°14.785' E18°33.666' 9 Little anchor
- S34°14.917' E18°33.753' 10 South east pinnacle chain (Neptune's bath plug)
- S34°14.935' E18°33.784' 11 Georgina's anchor
- S34°14.943' E18°33.549' 12 M&M Tower (the Spark plug)
- S34°14.943' E18°33.616' 13 Cave Rock reef
- S34°15.004' E18°33.580' 14 Labyrinth
Three other anchors have been reported. Two are said to be near the two currently recorded Euphrates anchors, between 27 and 30 m deep, and one is said to be near the 5 m pinnacle, lying flat on the bottom, and well camouflaged by encrusting growth. It probably does not have an iron or steel stock, or it would not lie flat, and so may be a relatively old anchor which had a wooden stock.
There is officially a navigation buoy slightly to the east of the reef, but there have been occasions when it was not there. The current buoy replaces the one which sank some years ago. Divers have reported that it lies on the bottom, still attached to its mooring system, and probably simply sank after years of neglect.
This site is partly in a Marine Protected Area (2009) The Eastern border of the Table Mountain National Park MPA passes through the west part of the reef area. Most of the reef is outside the MPA.
This area is marked on the SA Navy charts as a navigational hazard and named "Whittle Rock".
Maximum depth on the sand around the reef is more than 35 m. The top of the pinnacle is at about 5 m, but the variation is large due to the size of the site.
Visibility is often better than on the inshore reefs, but as with any False Bay reef, it is not very predictable, and there may be better visibility at the bottom below a dirty surface layer. When it is more than 10 m this site is particularly impressive, as the topography of pinnacles, gullies, walls, huge boulders and overhangs, with the occasional swimthroughs can be appreciated. Visibility can exceed 20 m on rare occasions.
Huge granite corestone outcrops and boulders. The topography varies considerably as it is such a large area of reef.
To the east and north of the shallows there is fairly deep water within a short distance, and the topography is steep and craggy, while to the north-west it is relatively flat. A reasonable idea of the local topography can be deduced from the chart.
Main pinnacle area The main reef area near the 5 m pinnacle is the shallowest part of the reef, with an extensive area above 15 m, and several areas above 12 m, separated by gaps and gullies of varying depth and width. Slightly to the east of the main pinnacle there is a long, deep and narrow gulley. To the immediate north and west is a plateau area between 10 and 15 m deep. There is said to be an anchor in this vicinity, but the precise position is not known.
Western pinnacle area This area includes several deep and steep sided roughly parallel ridges and gullies, mostly running roughly north-south, and a large swimthrough at about 18 m depth, where an enormous boulder is wedged into a large gully. This boulder is the western pinnacle. The other ridges and gullies are further west.
North-western pinnacle area There is a small, fairly steep and very localised pinnacle on a generally lower profile area of massive bedrock.
North-eastern pinnacle areaTo the north-east of the main pinnacle, there is a massive outcrop which rises to 15 m, with steep sides and flattish top. Just to the north of this are the anchors thought to be from the Euphrates wreck, in a sandy bottomed gully running from south-west to north-east, at about 25 m depth.
South-eastern pinnacle area The South-eastern pinnacle is a massive outcrop with its top at about 12 m, a steep wall on the north eastern side, and a flatter slope down to the south, where there is a sandy gully at about 30 m depth sloping down to the east, in which there is yet another large iron anchor on the boulder rabble on the north side of the gully. There is a large metal disc, somewhat less than a metre in diameter, at the end of a length of heavy chain on the sand on the north side of this gully, known as Neptune's bathplug. The gully has a few swim-throughs and small caves among the boulders at the bottom of the rock slope. The eastern side of this pinnacle slopes down quite steeply for a few metres to an area of moderate relief, which includes a few smaller gullies and swim-throughs, but then flattens out further to the east.
M&M Tower reefs The tower is also known as the Spark plug for the curved overhang at the top with a boulder just under it. It is a narrow ridge-pinnacle rising from about 24 m to about 11 m on top. It is about 50m west of the cave reef area, a group of huge boulders on a bedrock base at about 21m south-west of the main reef ridge. The M&M Tower is named for the two divers who found it by accident while diving from the Cave Reef area on a day of poor visibility. They ended up ascending at the tower and its position was recorded. This area has been quite extensively surveyed to 24 m, and it looks like the local maximum depth is about 27 to 30 m. It has become quite popular as it is fairly compact and has a lot of variation of topography. The high reef is about 100 m long from southeast to northwest, and about 30 m wide, with the tower roughly in the middle. The eastern section is a massive outcrop with a flattish top and a gnarled cliff face – the gnarly wall – on the northeast side, with a bus-stop overhang to the northwest at 18 m and indentations along the face of the wall formed by subsurface weathering of the granite, now exposed and covered by sea. The south side slopes down relatively smoothly to about 27 m, then low reef extends to sand at about 30 m, which can be considered the boundary of this reef section. The top of this outcrop is flattish and a bit above 15 m deep, with the shallowest point at about 13 m directly over the overhang. To the northwest it ends at a steep-sided gully running northeast-southwest with a narrow parallel ridge to the northwest, then another parallel gully of similar depth, and the tower ridge and boulder. Further west there are a few very large peaked outcrops separated by gullies of varied depth, in a cluster of similar size to the eastern part of the reef, but with a very different character. This can be seen fairly clearly from the map.
The Cave Reefs This is an area of high profile reef with a couple of pinnacles above 15 m north-east of M&M Tower reef across a flattish area about 27 m deep, roughly northeast of the Gnarly Wall and southwest of the Main Pinnacle area. This section of reef is somewhat chaotic in structure, and has several deep overhangs, and at least one fairly large but tight swimthrough. Survey is partial, and the full extent of the sector is not known yet. The southern extent of this section is demarcated by sandy strips running roughly northwest-southeast at about 25 to 30 m depth.
Labyrinth A compact cluster of ridge pinnacles of similar height rising from about 28 m on sand to about 15m at the shallowest points, separated by deep fairly narrow gullies, weathered from jointing fractures almost all the way down to the base depth in a crossing pattern. There are a few scattered boulders in the gullies, mostly quite small. The Labyrinth is bordered by patches of sand at the eastern edge, but with more relatively deep high-profile reef a short distance to the southeast. Spectacular in good visibility. Notable for large numbers of fragile scrolled bryozoan colonies. This parch of reef is about 70 m south from the east end of the M&M Tower reefs and is separated from it by a large sand patch at about 30 m depth.
Unexplored areas of interest There are a few places where local pinnacles or high spots have been identified by sonar, that are on the list of places to be mapped. A large swimthrough under huge boulders to the east of the Gnarly Wall and probably south of the Cave Reefs has been reported, but not yet surveyed. Watch this space.
Geology: Huge granite corestone outcrop with big weathered boulders of the late Pre-Cambrian Peninsula pluton, surrounded by a sand bottom
The site is exposed to wind and waves from all directions, however it is mostly quite deep, so short period waves will not affect conditions on the bottom greatly. Low short swell and light wind is best. There may be a thermocline, and the visibility may change significantly below the thermocline. Conditions at depth are not easily predictable, and may be better or worse than near the surface. There can be a plankton bloom in the surface layers and a sudden improvement in visibility from 3 m or less to over 10 m in the cold bottom water. The depth of the thermocline is also not very predictable, but has been known to be between 12 and 20 m There is no specific time of year for diving this site, you just have to wait for low swell and light winds.
A long period swell may produce significant surge at depth, depending on the local topography. In places the gullies will focus the surge, and in other places the high reefs and steep walls may provide relatively sheltered areas. Surface currents have been measured at up to about 1.5 kilometers per hour, probably caused by recent wind, and probably in a similar direction, or offset anticlockwise by the Coriolis effect.
Water temperature may vary with depth. The surface can be 18 or 19°C with 10 or 11° at the bottom, but the difference is more likely to be 5°C or less.
Much depends on which part of the reef you dive. There are a wide variety of invertebrates and quite a variety of fish seen in the vicinity, including shoals of Yellowtail. This is a popular fishing area and unfortunately there has been noticeable damage to the reef by anchors in the shallower parts.
The shallowest parts are dominated by large red-bait pods on the upper surfaces. Deeper areas have more sea fans and scrolled false corals, and below 20m there are more sponges. Some days there are shoals of fish, while on other days hardly any can be seem. This may be a function of water temperature and visibility. As is usual, there tends to be more diversity in areas of high rugosity and high profile, and on steeper slopes and under overhangs.
There are several large anchors. The approximate positions are known for eight of them, and shown on the map.
- Two large iron anchors with iron stocks, thought to be from the English East-Indiaman Euphrates which struck the pinnacle and sank in 1810, at 25 m depth, in a sandy bottomed gully at S34°14.783, E18°33.795 and S34°14.776, E18°33.801. Two more anchors are reported from near this point. All are between 24 m and 28 m depth.
- A large anchor with iron stock at 17 m depth, at approximately S34°14.781, E18°33.721, (JJ's anchor)
- An anchor at 18 m depth, at approximately S34°14.736, E18°33.592 (Riaan and Sven's anchor)
- An iron anchor at 18 m depth, at approximately S34°14.785, E18°33.666 (Little anchor)
- A large iron anchor at 15 m depth, at approximately S34°14.767, E18°33.575 (September anchor)
- A large iron anchor at the base of the south slopes of the south-eastern pinnacle, of unknown provenance, at a depth of 29m. (Georgina's anchor)
This is a good site for photography. Macro is a safe bet, as there will always be subjects for close up work. If the visibility is good, and it can be better than 20 m occasionally, wide angle scenic shots are an option. Good visibility and good natural lighting together are relatively uncommon.
At this stage no particular routes are recommended, but a swim around the 15 m contour is a good option for a fairly long dive with lots of scenic views if the visibility is good, and some excursions to the pinnacles.
If there is a lot of surge in the shallows, which is common in a long period swell even when the swell is quite low, the deeper areas will be more comfortable and possibly safer. The reef life also varies with depth and topography, and to get a good idea of what all can be found it is necessary to explore a reasonably large range of depths. Visibility and water temperature are somewhat unpredictable, and can differ from the inshore dive sites. There may be a thermocline, and visibilty at the bottom can differ quite a bit from nearer the surface. Even at 3 to 4m visibility it can be a good dive.
You could return to Whittle Rock every weekend for a year and not see it all. It is big, with a huge variety of topography and large depth range, and is highly rated by local divers who have actually dived there often enough to develop a reliable opinion.
Cold water is possible. Strong winds may develop over a short time, particularly in summer. Great white sharks have been seen in this area. Poor surface visibilty can occur occasionally, and if there is a surface current, a diver could drift quite a long way during ascent, making it difficult for the boat to find them.
Much of the reef is fairly deep and beyond the range of novice divers, but there are also extensive shallower areas. The ability to deploy a DSMB is recommended, as this will help the boat crew to see you after the dive, and will warn fishing boats of your presence while surfacing. On some occasions there may be large numbers of small craft fishing in this area, and some of the skippers do not pay much attention to where they are going.
A light is helpful both in deep areas to compensate for the loss of colour, and wherever there are deep cracks, overhangs and other dark areas. A compass is mostly useful for heading towards a planned point, as when heading towards a shallower area at the end of a dive. An SMB is strongly recommended to help the boat keep track of your position, or to find you when you ascend. Nitrox is generally useful to extend no-stop dive times as most dives at Whittle are fairly deep. The water temperature may be low, so good thermal insulation is also recommended.
- 1 Seal Island
- 2 Drop Zone
- 3 East Shoal
- 4 Moddergat
- 5 York Shoal
- 6 SAS Fleur
- 7 Steenbras Deep - North Pinnacles
- 8 Steenbras Deep - South Pinnacles
- 9 SATS General Botha
- 10 SAS Bloemfontein
- 11 Bellows Rock
- 12 SS Lusitania
- 13 Rocky Bank