Joao de Lisboa (that is, Joao of Lisbon), one of the most famous Portuguese navigators and port pilots of the fifteenth and sixteenth centuries, probably sailed to India with Vasco da Gama* in 1497. It is possible that he was aboard a Portuguese vessel that entered the Rio de la Plata, Argentina, shortly after 1500, and his name appears in several places on early maps of Brazil. In 1506 he travelled to India in a fleet under the command of Tristao da Cunha. At some time, while in Cochin (now Kochi), India, he compared two methods of determining latitude, one using the altitude of the Pole Star (measured with a quadrant), the other based on the altitude (at a specified position) of alpha Crucis, the brightest star of the southern cross. Both these stars were visible from Cochin. The method based on the altitude of alpha Crucis had been developed in 1500 by "Mestre Joao", who had been sent with the fleet of Pedro A. Cabral to Brazil for this purpose. It became widely used in the southern hemisphere (where the Pole Star cannot be seen) during the mid-sixteenth century.
In 1513 Joao was a pilot on an expedition to Morocco. Later he may have accompanied the global circumnavigation led by Ferdinand Magellan during 1519-1522. In 1514 he started compiling his Tratado da agulha de marear, as part of a larger work on navigation and sailing directions which included 20 maps of various parts of the world. Attached was his Llivro das Rotas de Lixboa ate a India, a pilot book of the route to India, which included a detailed description of the southern African coast. The work was eventually edited by J.I. de Brito Rebello and published under the title Livro de marinharia. Tratado da agulha de marear... (Lisbon, 1903, 308p). An English translation of the pages relating to South Africa was published by Axelson (1988, pp. 14-27).
Joao's description of the South African coast was much more detailed than earlier attempts by Pacheco Pereira* and others. Though he gave no latitudes of places of interest, he provided many details relating to the appearance of the land as seen from a ship, describing capes, bays, mountains, hills, sand dunes, shoals, and even prominent rocks and concentrations of trees. Both De Kock (1957) and Axelson (1988) considered his description to be the most comprehensive and accurate of all by a Portuguese navigator, and not improved upon until the nineteenth century.