Diving the south coast of South Africa

From a diving perspective, the south coast can be considered to extend from about Danger Point at Gansbaai eastward to the far side of the Wild Coast. The region is dominated by the huge and powerful Agulhas Current, which flows south-west along the eastern part of this coast and is forced away from the coast by the widening continental shelf, allowing cooler water to push in along the shore, and breaking off enormous eddies. Rivers flow into the ocean along this coast and, as there is no strong inshore current to carry these waters away, their nutrient load is dispersed relatively gradually compared with the east coast. Many endemic species have evolved in this region. These are animals which are found nowhere else, and some of them have very limited ranges. For example, the Knysna seahorse is only found in three estuaries on the south coast. Many south coast animals and seaweeds have ranges which also extend along the east and west coasts, depending on their temperature tolerances, and there are also cosmopolitan and migratory species.

General topography

The south coast, for the purposes of recreational diving, is considered to extend from about Danger Point close to Hermanus all the way east to Port Edward, in the south of KwaZulu-Natal. This coastline borders part of the Western Cape and the whole of the Eastern Cape. It is a coastline known for rugged beauty and geographic diversity: huge cliffs, vleis and lagoons, river mouths in impressive gorges; even a waterfall that plummets directly into the sea. About 80 km south of Struisbaai the Alphard Banks are the southernmost dive sites of the African continent. These are sea mounts on the continental shelf which rise from 80 to 14 m depth in places. They are spectacular places to dive because of their proliferation of fish, but they are a long way offshore.

Climate, weather and sea conditions

This region has higher sea surface temperatures than the west coast, reaching 22ºC in summer and averaging around 15ºC in winter. When dive conditions are good, there is a unique biodiversity to be explored in water that is not particularly cold.

Marine ecology

Under the water, the marine life is diverse and profuse. The majority of animals found in this region are endemic to the the southern African coast. Conditions can be challenging, and large parts are seldom dived. Species new to science are frequently discovered. The very first living coelacanth that was brought to the attention of western scientists was caught in this region, but there have been no further sightings.
Powerful natural forces have contributed towards the south coast marine environment. The Agulhas Current follows the coast until it is pushed offshore of the south coast by the widening of the continental shelf in this area. Because of the offshore deflection of the current in this area, the larvae of species brought south by the current have little chance of settling out onto a reef, so new species seldom establish on this coast. Inshore marine life is thus relatively isolated from the rest of the world ocean, and a fertile environment has long existed for species to evolve to suit the region.

The marine ecoregions

The regions of interest to recreational divers are the coastal ecoregions, which are considered to extend from the shoreline to the break of the continental shelf, so most of each ecoregion is far too deep to dive.

• The warm temperate Agulhas ecoregion extends from Cape Point to the Mbashe River, and is the major marine ecoregion of the south coast. The Mbashe River was chosen as the most appropriate boundary between the subtropical Natal province to the north, and the warm temperate Agulhas region to the south, but change is gradual between these regions. Upwelling on the south coast of South Africa is largely driven by the Agulhas current and the continental shelf. This form of upwelling forces cold deep water up onto the continental shelf, but not necessarily above the thermocline. In the region east of the Agulhas bank, wind enhanced upwelling, occurring mainly in summer, augments the current driven upwelling bringing the colder deeper waters to the surface. This enhances biological productivity by supply of nutrients to the euphotic zone (where plants have sufficient light to flourish) which fuels phytoplankton production, and rocky shores that are supplied with the nutrient rich water support rich algal biomass.
• The subtropical Natal ecoregion covers the rest of the coastline through Port Edward in southern KwaZulu-Natal. The Natal ecoregion extends from the Mbashe River to Cape Vidal. This area has high riverine input. but the Agulhas Current is the major influence on the Natal bioregion. Reef habitat is limited and the major reef areas include Aliwal Shoal and Protea Banks. The rocky reef communities are distinct from the coral reef communities further north as stony corals decline with increased turbidity to the south. The Natal ecoregion supports endemic soft corals. The annual sardine run is a feature of the southern portion of this region.

The annual chokka (squid) spawning and the sardine run take place largely in this region.

Equipment

The equipment recommended is basic scuba equipment with good thermal insulation. A 5 mm wetsuit is good enough for some divers, but others prefer a 7 mm wet suit or a dry suit with an appropriate undersuit, particularly for longer, deeper or multiple dives, and when the temperature is lower. Hood and booties are recommended, though occasionally divers have been known to do without. Gloves are considered optional for insulation, but even a thin pair will provide some protection against stings and abrasion.

• A dive light is an option for most dives, but there are many places where having an artificial light source will greatly enhance the dive.
• A deployable surface marker buoy (DSMB) is strongly recommended for boat dives, particularly when there is a choppy surface, a strong wind, or the dive plan does not include surfacing at the shotline.
• Sufficient weight to allow a controlled safety stop with near empty cylinders, but not so much that buoyancy control at depth is compromised, and definitely not so much that the buoyancy compensator cannot provide neutral buoyancy at all planned depths and positive buoyancy at the surface. As a first approximation the BC should be able to support all the lead, and the lead should be able to sink the suit.
• A permit is required to dive in MPAs, but the same permit is good for any MPA in South Africa.
• Other equipment may be necessary or desirable to suit a specific dive plan.

Western Cape

The Western Cape province is the most south western province in South Africa. It includes a large proportion of South Africa's tourist destinations and attractions, amongst which are several of the better known diving destinations.

Quoin Point

• — ran aground on a reef off Quoin Point in 1948

Struisbaai

Struisbaai is a small fishing village in the Overberg district of the Western Cape
Dive sites include:

• - popular spearfishing area

Arniston (Waenhuiskrans)

Arniston is a small holiday town in the Overberg district of the Western Cape, named after its best known wreck.
Dive sites include:

• Saxon Reef

Mossel Bay

Mossel Bay is a harbour town on the Garden Route in the Western Cape
Dive sites include:

• Phluffy Reef

Knysna

Knysna is a harbour town on a large lagoon on the Garden Route in the Western Cape. Diving near the mouth of the lagoon is best done at high tide, as the currents can get very strong.
Dive sites include:

• Christmas and New Year
• Thesen's Jetty - Sometimes you may see the elusive and endangered Knysna seahorse in the weed beds

Plettenberg Bay

Plettenberg Bay is a holiday resort town on the Garden Route in the Western Cape, known mainly for its beaches.
Dive sites include:

• Dolphin Column
• Playground
• Virgin reef
• Voorstraat (The Island)

Eastern Cape

The Eastern Cape is a province on the south coast of South Africa on the coast of the eastern part of the Agulhas ecoregion, which is rich in endemic marine species.
Diving is very dependent on weather conditions, and visibility is mot often good, but when it is good there is a lot to see. The water is generally warmer than the Western Cape, but there are occasional cold upwellings.

Tsitsikamma

extends along the western part of the Eastern Cape coast and a small part of the Western Cape coast on the Garden Route.

Jeffrey's Bay

Jeffrey's Bay is a holiday resort town on the Eastern Cape best known as a surfing destination.
Dive sites include:

St Francis Bay

St Francis Bay is a small harbour town on in the Eastern Cape, known for the annual Chokka run.
Dive sites include:

• Bell buoy reef
• Daggie Banks

Port Elizabeth

is a major port city in the Eastern Cape on the shores of Algoa Bay, The dive sites are both inside the bay and to the west of Cape Recife, in and area known as the Wildside, which is more exposed to south-westerly swells, but is deeper and has more extensive reefs

Port Alfred

Port Alfred is a small harbour town in the Eastern Cape at the mouth of the Kowie River.
Dive sites include:

• The Briseis
• The Chain
• Computer reef (Riet 40)
• Eden
• Fish Tanks
• Fountain Reef
• Janssen's Rock
• Kowie River
• Riet Point
• Shark's Gully
• Soft Coral Reef
• Towers
• Umvolusi

SS Cariboo wreck

is the wreck of a passenger steamer about 3.4 km off the mouth of the Mgwalana river, northeast of Port Alfred.

Madacascar reef

Just to the north of the Bira river mouth, about 70 km north east of Port Alfred.

East London

East London is a port city in the Eastern Cape.
Dive sites include:

• The Boulders
• Nahoon Bay
• Queensbury Bay
• Small Pier
• Wagon wheels

Wild Coast

The Wild Coast is the coastal region of the Eastern Cape from north of East London to the southern border of KwaZulu-Natal.
Dive sites include:

Emergency services

• Recompression facilities —
• Divers Alert Network (DAN) has a branch in South Africa Their toll free line from within the country 0800 020 111, and regular line

*27 (0)11 254 1112 will get you the 24-hour emergency hotline. If you are a DAN member and are involved in a diving accident, contact them first and they will make the necessary arrangements through whichever other organisations are most appropriate.

• National Sea Rescue Institute contact details

• Sea Rescue emergency number from cell phones - 112

Western Cape:

• Agulhas - 082 990 5952
• Plettenberg Bay - 082 990 5975
• Still Bay - 082 990 5978
• Wilderness - 082 990 5955

Eastern Cape:

• East London - 082 990 5972
• Jeffreys Bay - 079 916 0390
• Oyster Bay - 082 990 5968
• Port Alfred - 082 990 5971
• Port Elizabeth - 082 990 0828
• Port St Johns - 082 550 5430
• St Francis Bay - 082 990 5969

Ambulance - 10177

Police - 10111. Emergency calls to ambulance or police numbers will be routed to the relevant Sea Rescue authority if you do not have the local Port Control number.

== Read ==
Branch, G. and Branch, M. 1981, The Living Shores of Southern Africa, Struik, Cape Town.
Branch, G.M. Griffiths,C.L. Branch, M.L and Beckley, L.E. Revised edition 2010, Two Oceans – A guide to the marine Life of Southern Africa, David Philip, Cape Town.
Gosliner, T. 1987. Nudibranchs of Southern Arica, Sea Challengers & Jeff Hamann, Monterey.
Heemstra, P. and Heemstra E. 2004, Coastal Fishes of Southern Africa, NISC/SAIAB, Grahamstown.
Ed. Smith, M.M. and Heemstra, P. 2003 Smith’s Sea Fishes. Struik, Cape Town. (Authoritative, large and expensive)