Diving at East Shoal
The dive site East Shoal is an offshore rocky reef in False Bay, near Cape Town in the Western Cape Province of South Africa.
Understand
[edit]The site is seldom dived, as it is far from the nearest launch sites, and relatively close to Seal Island where Great White sharks are frequently seen predating on the Cape fur seals which breed there.
Position
[edit]S34°08.9' E018°38.783' 1 East Shoal approximately on the top of the reef.
This is an offshore site about half-way across False Bay from the Cape Peninsula to the east side, and about 1/4 of the way south from the north shore between Strandfontein and Macassar. There are no landmarks other than the waves which usually break on top of the reef. The reef never extends above the surface of the sea.
This site is not in a Marine Protected Area (2010). A permit is not required.
Name
[edit]The name "East Shoal" is marked on charts of the area, and is descriptive of its position in False Bay. It is the most easterly shallow offshore point in the bay.
Depth
[edit]Maximum depth is probably about 25 m, and the top of the reef is probably about 2 m deep at low tide. The shoal is noted to break on the SAN charts, and it has been observed to break in a fairly flat sea.
Average depth of a dive is likely to be between 15 and 20 m. Surge is strong near the pinnacle.
Visibility
[edit]Visibility will be similar to other offshore reef sites of False Bay, and is likely to be between 3 and 10 m. This may differ considerably between the surface waters and the bottom, and may be better or worse than it appears from the boat.
Topography
[edit]The site is an extensive area of sedimentary rock. Some is fairly high profile, walls of several metres height have been seen on the east side, but more often the reef is moderate to low profile, but fairly rugose, as the rock has frequent steps and cracks, and the dip is fairly steep, at about 30°, roughly to the east.
Geology: Thought to be Sandstone of the Table Mountain Series, based on visual description and similarity to the reef at Rocky Bank. The rock appears to be of fairly consistent resistance to weathering and erosion. Strike is approximately North-South magnetic. Dip is roughly eastwards, and fairly steep, estimated about 30°.
Conditions
[edit]The site is exposed to swells from the south west, and wind chop from any direction, so should be dived in flat seas, which may occur at any time of the year, but not frequently. If dived during the summer, pay attention to local weather forecasts as the south-easter may come up strongly over a short time. This may make it difficult for the boat crew to spot divers in the water, but is unlikely to be noticed by divers on the bottom. It will also make the ride home wet and uncomfortable if operating out of Gordon's Bay.
This is an area which sometimes has red tides and thermoclines. Red tides generally reduce the surface visibility significantly, but may have less effect at depth. Thermoclines will result in the bottom water being colder than the surface, which can be an unpleasant surprise and cause you to get cold more quickly, but is not otherwise a hazard.
Get in
[edit]Boat access only. The site is several kilometers from the nearest shore.
The site is about 18.4 km bearing 084° magnetic from the slipway at Miller's Point, or 19.3 km bearing 295° magnetic from Harbour Island in Gordon's Bay. It is about 8 km from the north shore of False Bay
See
[edit]Marine life
[edit]The site appears to be very suitable for echinoderms. There is no obvious reason, but much of the reef is covered by a mat of brittle stars, and other areas have a dense cover of red-chested sea cucumbers. There are also large numbers of Cape urchins, common and elegant feather stars, mauve sea cucumbers, and moderate numbers of other starfish, including Basket stars, Spiny starfish, Red stars, Granular starfish and Reticulated starfish.
The fish life does not appear to be very prolific, but Roman, Redfingers, Barred fingerfin, Two-tone fingerfin and puffadder shysharks have been seen, Great white sharks have been reported from nearby by fishermen, but have not yet been seen by scuba divers.
Black sponges are common and are associated with an unusual shrimp, which may well be an undescribed species. There is also a variety of neon yellow hydroids not seen on the western side of False Bay. Nudibranchs seem uncommon, despite significant food sources in the form of purple soft corals, hydroids and bryozoans.
Other reef life is similar to the reefs of the east side of False Bay and includes moderate numbers of Sinuous and Multicolour sea fans, a few Palmate sea fans, a fair variety of sponges and colonial ascidians, a few species of sea squirt, including large pods of "red bait", hydroids, bryozoans and anemones. Very little seaweed other than crustose corallines is to be seen below 10 m.
The reef is carpeted by brittle stars over large areas
Juvenile red-chested sea cucumbers
Some of the echinoderms found at East Shoal
Photography
[edit]The visibility is unpredictable, so close-up and macro equipment is most likely to give good results. Particulate matter will cause backscatter when the subject is more than a few cm from the camera lens port, so an external strobe is recommended for photos other than macro and close-up work.
Suggested Routes
[edit]No specific roures are known. Start deep, around 20 to 25 m, not more than 150 m from the pinnacle, and work your way uphill until the surge becomes excessive, then head away while surfacing, so the boat does not have to approach the breakers too closely.
The site is largely unexplored, and no data is available on the south, west and north sides of the pinnacle. If you dive one of these areas, please feel free to contribute your observations.
Stay safe
[edit]Hazards
[edit]Great White Sharks feed at Seal Island, but this is several kilometers away. Scuba divers have not yet reported sightings of Great Whites at East Shoal, however it might not be prudent to hang around in midwater or on the surface for long. Decompression dives are not recommended for this reason.
The swell breaks on the pinnacle in most sea states, and the surge will be dangerous at the top. Use your own judgement to decide how close to the pinnacle to dive, but move away when surfacing, as the boat will not be able to approach too close to pick you up in the surf zone.
Skills
[edit]No special skills required. Reasonable fitness is recommended, and the ability to swim a compass course could be useful.
Equipment
[edit]A compass is useful for navigation, though depth is generally sufficient indicator of where to go. A deployable SMB will allow the boat to be ready to pick you up when you surface, and avoid long periods waiting for a pickup or swimming at the surface.
Nearby
[edit]
Other offshore dive sites of False Bay:
- 1 Choirboys Reef
- 2 Seal Island
- 3 Drop Zone
- 4 Moddergat
- 5 Sterretjies Reef
- 6 York Shoal
- 7 SAS Fleur
- 8 Offshore Barges – North Barge
- 9 Steenbras Deep - South Pinnacles
- 10 Blue Flame Pinnacles
- 11 SATS General Botha
- 12 Off-Whittle Ridge
- 13 SAS Bloemfontein
- 14 Whittle Rock
- 15 Bruce's Mark
- 16 Deep South Whittle Reef
- 17 SS Lusitania
- 18 Rocky Bank
Back to the Alphabetical list of sites, or list of reef dive sites in the northern False Bay offshore area
Other regional dive sites:
- Dive sites of Table Bay and approaches,
- Dive sites of the Cape Peninsula west coast
- Dive sites of the Cape Peninsula east coast
- Dive sites of False Bay east coast
- Fresh water dive sites of the Cape Town Metropolitan Area