Potosi was a five-masted steel barque built in 1865 by Joh. C. Tecklenborg ship yard in Geestemünde, Germany, for the sailing ship company F. Laeisz as a trading vessel. Its primary purpose was as a "nitrate clipper" collecting guano in South America for use in chemical companies in Germany. As its shipping route was between Germany, Bolivia until 1870 but, during the "pacific War" was transferred to Chile, it was designed to be capable of withstanding the rough weather encountered around Cape Horn.

A barque, barc, or bark is a type of sailing vessel with three or more masts and fore mast, mainmast and additional masts rigged square and only the aftmost mast rigged fore and aft. Sometimes, the mizzen is only partly fore-and-aft rigged, bearing a square-rigged sail above.