The continent of Africa has had a lengthy involvement in global maritime affairs and archaeological research with Middle Stone Age people using marine resources on the coasts of southern Africa, the Classical Pharos lighthouse of Alexandria, and Medieval Indian Ocean trade on the Swahili coast to the Atlantic triangular slave trade. Maritime archaeology is the identification and interpretation of physical traces left by people who use the seas and oceans. Middle Stone Age sites in South Africa such as Klasies River Mouth and Pinnacle Point have the earliest evidence for human use of marine resources including birds, marine mammals, and shellfish. This exploitation of marine resources was also coincident with the use of pigment, probably for symbolic behavior, as well as the production of bladelet stone tool technology. The extensive timespan of human activity on the coast around Africa occurred during changing relative sea levels due to Ice Ages and tectonic movement affecting the location of the coastline relative to maritime archaeological sites. Geomorphological changes may also take place over shorter periods such as the 1909 ce shipwreck of the Eduard Bohlen in Namibia lying c. one and half thousand feet landward of the shoreline.
Ancestors of sea-going vessels have been recorded on rivers from dugout canoes excavated at Dufuna in northern Nigeria and the first plank-built boats, such as the Old Kingdom Royal Ship of Cheops of Khufu, found at the Giza pyramids, which imitated the shape of earlier papyrus rafts. Classical documents such as the Periplus Maris Erythraei and Ptolemy’s Geographia record Arabian and Indian trade with eastern Africa including ivory and rhinoceros horn and describe fishing practices using baskets and sewn-hull boats of the inhabitants. The increase in oceanic trade links here during the medieval period encouraged the formation of Swahili port cities such as Kilwa and Mombasa. The former was in a strategic position to manage much of the gold trade between Sofala in Mozambique and the northern Swahili Coast. Portuguese forts, constructed in the 15th and 16th centuries on their trade routes around Africa, such as Elmina Castle in Ghana, Fort Jesus in Mombasa, Kenya, and Fort São Sebastião on Mozambique Island, dominate the ports and harbors. The first sub-Saharan underwater scientific investigations took place in 1976 of the Portuguese frigate Santo Antonio de Tanna that sunk during an Omani siege from 1696 to 1698. At Elmina in West Africa, studies were made of wreck-site formation processes around the 17th-century Dutch West India Company vessel Groeningen, which had caught fire when firing its guns in salute to Elmina Castle after arrival. More broad-based studies that interpret the functioning of the African maritime society in its wider environmental setting, both physically in the context of its religious buildings, harbors, fishing grounds, sailing routes, and shipwrecks, and by taking account of non-material aspects of the beliefs that influence behavior of coastal societies, have led to interpretations of their maritime outlook.