The Shipwrecks of Cape Town are the shipwrecks in the waters of the Atlantic Ocean in the vicinity of Cape Town, South Africa. They include any wreck that is in the waters off the shores of the City of Cape Town metropolitan area, and those which are now inshore of the high-water mark due to land reclamation, shifting sands, or being cast up by stormy seas. The geographical area extends from Silwerstroomstrand north of Robben Island, Table Bay, around the Cape Peninsula and False Bay to the vicinity of Kogel Bay on the east side of False Bay. Several of these wrecks are suitable sites for recreational scuba diving, and may be described in dive guides for the region. Others are inaccessible due to depth or being on the shore, or buried under sediments or landfill, and some have not yet been found or identified.
Some of the wrecks carried valuable cargo, and where practicable salvage efforts have been made to recover such cargo. On other occasions cargo and fuel have been recovered as far as reasonably practicable to mitigate the effects on the environment of hazardous materials.
Some of the wrecks are classified as historically important and are legally protected as part of the national heritage, and some of these have been studied as archaeological sites.
Geographical context The coastline of Cape Town is roughly 307 km long, from Silwerstroomstrand at on the west coast to slightly south of Kogelbaai at on the east coast of False Bay. The coast may be subdivided into the Bloubergstrand (the northern part of the mainland coast), Robben Island, Table Bay, the Atlantic Seaboard (west coast of the north peninsula), Hout Bay and the South Peninsula west coasts, and the False Bay west, north, and east coasts.
The coastline between the large rocky promontory at Bokpunt and Silwerstroomstrand and the harbour wall at the current mouth of the Salt River, is mostly a long sandy beach with a few small, and low rocky promontories. Much of the coastline of Table Bay has been modified by coastal and civil engineering works for the Port of Cape Town. As a consequence a significant number of wreck sites in the region have been covered by land reclamation work between the Salt River mouth and Mouille Point.
Hydrographic characteristics
Tidal range is moderate, with about 1.8 to 1.9 m range at spring tide on both sides of the peninsula, and tidal currents are negligible.
Bathymetry
The bathymetry of False Bay differs in character from the west side of the Cape Peninsula. The west coast seabed tends to slope down more steeply than in False Bay, and although the close inshore waters are also shallow, the 100 m contour is mostly within about 10 km of the west coast, while the entire False Bay is shallower than about 80 m. The bottom of False Bay slopes down relatively gradually from the gently sloping beaches of the north shore to the mouth, and is fairly even in depth from east to west except close to the shorelines. Table Bay is relatively shallow, and slopes gently from east to west, reaching a maximum depth of 35 m at the centre of its mouth. The bottom is mostly fairly low reef of hard shales, slates and sandstone of the Malmesbury group, similar to the shores to the south and north, with extensive patches of fine and coarse sand
Navigational hazards Albatross Rock (L'Alouette 1817, SS Albatross 1863, RMS Kafir 1878, Star of Africa 1880, SS Umhlali 1909, SS Bia 1917, MV Nolloth 1965) Anvil Rock (Colebrooke 1778) Batsata Rock Bellows Rock (Unity 1859, Paralos 1880, Lusitania 1911) Cape Point East Shoal Roman Rock Seal Island Vulcan Rock Whale Rock (Nieuwe Rhoon 1776, Perseverance 1826, Forfarshire 1864, SS Hypatia 1929, MFV Fong Chung No.11 1975, MV Daeyang Family 1986, MFV Afrikaner 1993) Whittle Rock York Shoal
Weather patterns
Cape Town has a Mediterranean climate (Köppen: Csb, bordering Csa), with mild, moderately wet winters and dry, warm summers. Winter, which lasts from June to September, may see large cold fronts entering for limited periods from the Atlantic Ocean with significant precipitation and strong north-westerly winds. Winter months in the city average a maximum of and minimum of .
Summer, which lasts from December to March, is warm and dry with an average maximum of and minimum of . The region can get uncomfortably hot when the Berg Wind, meaning "mountain wind", blows from the Karoo interior.
Spring and summer generally feature a strong wind from the south-east. This wind is caused by a persistent high-pressure system over the South Atlantic to the west of Cape Town, known as the South Atlantic High, which shifts latitude seasonally, following the sun, and influencing the strength of the fronts and their northward reach. Cape Town receives about 3,100 hours of sunshine per year.
Unlike other parts of the country the city does not have many thunderstorms, and most of those that do occur, happen around October to December and March to April.
Winds The winds have a strong influence on the waves and water circulation. The wind follows a characteristic pattern, which shifts in latitude with the seasons and follows the Rossby waves as they move eastwards over the southern ocean. A southwesterly wind follows the passage of a cold front as the anticyclone moves east and merges with the South Atlantic High, producing strong south-easterly winds. The high pressure cell moves further over the tip of Africa and splits off the South Atlantic High, with weakening south easterly winds, followed by a coastal low with north-westerly wind before the next cold front, bringing cool, wet westerly wind which passes around Table Mountain and converges as a northerly wind over False Bay.
The South Atlantic High shifts latitude with the seasons, following the sun, and this causes a large variation in the wind pattern over the passage of the year. In summer it moves south and the south-easterly winds dominate, and on average are strongest during January and February. During winter the northward shift allows the fronts to extend further north with stronger north-westerly winds and more frequent and heavier rain. The winter winds tend to be strongest in June and are generally northwesterly. The transition periods are around April and September.
The El Niño–Southern Oscillation (ENSO) affects the winds and rainfall over this region. During El Niño the south-easterly winds, while during La Niña the same winds are stronger. These effects on the winds are part of large scale influences on the tropical Atlantic and the South Atlantic High-pressure system, and changes to the pattern of westerly winds further south. There are other influences not known to be related to ENSO of similar importance. Some ENSO events do not lead to the expected changes.
Local variations in wind direction and strength are caused by interaction with the mountains on both sides of False Bay. South-easterly winds are accelerated northwest of Cape Hangklip, and a distinct wind shadow can develop in the lee of the Kogelberg mountain. Northwesterly winds accelerate over Table Mountain and approach False Bay from varying directions depending on the local topography. Temperature differences between land and water can also produce diurnal variations of wind speed and direction, particularly in summer.
Eastward-moving atmospheric Rossby waves move across the area at 3 to 20 day intervals, mostly in winter from May to September, and the subtropical ridge is replaced by coastal lows followed by northwesterly winds and frontal troughs that bring rain, stormy winds and seas.
Waves The prevailing swell around Cape Town is long period (12 to 15 secons) swells from the southwest with an average height of about 3 m. These swells are generated far offshore to the southwest of the continent, and the anchorages at both Table Bay and Simon's Town are well protected from them.
Storm waves are generated by northwest gales in winter and southeast gales in summer. Table Bay is very exposed to wind and waves from the northwest, but well protected from waves from the southeast, while Simon's Bay and the other western False Bay anchorages are exposed to southeast wind and waves, except where harbour breakwater structures have been built.
History
The history of the shipwrecks of Cape Town is part of the history of the shipping route around Africa, the history of the colonisation of South Africa and the history of the people of the region once they reached the stage of operating shipping in these waters.
The wrecks include those of explorers, traders, fishing vessels, passenger vessels and warships, sunk by misadventure, acts of war, military exercises, to create artificial reefs, and to dispose of redundant equipment.
Significance of the region
The European-Asian sea route, commonly known as the sea route to India or the Cape Route, is a shipping route from the European coast of the Atlantic Ocean to Asia's coast of the Indian Ocean passing by the Cape of Good Hope and Cape Agulhas at the southern edge of Africa. The first recorded completion of the route was made in 1498 by Portuguese explorer Vasco da Gama, the admiral of the first Portuguese Armadas bound eastwards to make the discovery. The route was most important during the Age of Sail, but became partly obsolete after the Suez Canal opened in 1869.
Cape Town is a major port city historically serving a large part of the hinterland of South Africa. It has two major harbours, the Port of Cape Town in Table Bay, and the Simon's Town Naval Base, in False Bay. It has intermittently heavy international sea traffic, and anchorages which are protected in some weather conditions and exposed in others. It is variously known as the Cape of Storms, and the Cape of Good Hope. It exhibits the characteristic features of a "shipwreck graveyard", in that it has had high shipping traffic over a long period, has several major navigational hazards, frequent bad weather conditions, was poorly charted for quite a long time, and has a major port with exposed anchorages, often containing a fairly large number of ships. An additional reason for some of the wrecks is scuttling to dispose of obsolescent equipment. As a major fishing harbour during the 20th century, there were frequently old fishing vessels to be disposed of, and in the days before electronic navigational aids, collisions in the anchorage and harbour approaches during bad weather and fog were more frequent. The initial establishment of a settlement at the Cape which became Cape Town was a consequence of its position on the trade route, and was influenced by some of the wreckings, and the availability of fresh water. Establishment of Cape Town
In 1647, the Dutch East Indiaman Nieuwe Haerlem was wrecked near the northeastern shore of Table Bay. The crew, with one exception, got off safely, and some were taken aboard by another Dutch ship and two English ships, while the rest stayed to attempt to salvage the cargo. These men also built a fortified shelter and explored the vicinity. They and the cargo they were able to salvage were taken back to the Netherlands by the returning Verenigde Oostindische Compagnie (VOC) fleet of the following year. A report by two of the men to the directors of the VOC persuaded them of the potential benefits of a refreshment station at Table Bay, and in 1652, Jan van Riebeeck was sent to the Cape to establish such a refreshment station.
Great gales and the harbour