Classicly

Dick Sand, A Captain at Fifteen is a Jules Verne novel published in 1878. It deals primarily with the issue of slavery, and the African slave trade by other Africans in particular. Several adaptations were made, two Soviet and one Franco-Spanish. 

Dick Sands, a youth of fifteen, must assume command of a ship after the disappearance of its captain. Nature’s forces combined with evil doings of men lead him and his companions to many dangerous adventures on sea and in Central Africa.