Beginning in 1677, Royal Navy regulations for promotion to lieutenant required service as a midshipman, and promotion to midshipman required some time at sea. By the Napoleonic era, the regulations required at least three years of services as a midshipman or master's mate and six years of total sea time. Sea time was earned in various ways, most boys served this period at sea in any lower rating, either as a servant of one of the ship's officers, a volunteer, or a seaman.