During the following four years at sea, Shackleton learned his trade, visiting the far corners of the earth and forming acquaintances with a variety of people from many walks of life, learning to be at home with all kinds of men. In August 1894, he passed his examination for second mate and accepted a post as third officer on a tramp steamer of the Welsh Shire Line. Two years later, he had obtained his first mate's ticket, and in 1898, he was certified as a master mariner, qualifying him to command a British ship anywhere in the world.