The ancient Egyptians and the Kushites were some of the earliest people to use sails for their boats.The earliest record of a ship under sail is depicted on an Egyptian pot dating back to 3200BC.The Dufuna canoe found in Nigeria by Fulani hersdmen is the oldest boat found in Africa at between 8500-8000 years old. Sailing in West Africa is considered influenced by European contact in the 15th century.One of the earliest accounts of boats with sails is from Duarte Lopez who lived in the Kongo Kingdom from 1578-1597. Here is his account of Congo natives using sail boats.
" In this island the boats are made from the trunks of palmtrees joined together. They have prow and stern, oars and sails, and are used by the natives for catching fish, which abound along these coasts; they also sail in them to the mainland."
source : A Report of the Kingdom of Congo: And of the Surrounding Countries;Drawn out of the Writings and Discourses of the Portuguese,Duarte Lopez,by Margarite Hutchinson,p.19, 1881