Late in the 13th century, the Mongol navy was the world's largest. It was, however, almost completely destroyed by storms and typhoons in two failed attemps to invade Japan.
Today, Mongolia is landlocked, and their navy is consequently somewhat smaller, being just one ship, the Sukhbaatar, and seven sailors, one of whom can swim.
Originally, the ship was built to transport Soviet oil across Lake Hovsgol, the world's fourteenth-largest freshwater lake. However, in the 1990's, the government became concerned about polluting the lake, one of the world's most pristine. Thus oil shipments ceased and the navy was privatized, and now, it can be hired for private cruises for some 120 dollars per hour.
The Mongolian government has published The Comprehensive History of the Mongolian Navy – on a single, folded sheet of paper.