A seaman.

An Excerpt from Joseph Conrad's Heart of Darkness:

"He was a seaman, but he was a wanderer too, while most seamen lead, if one may so express it, a sedentary life. Their minds are of the stay-at-home order, and their home is always with them - the ship; and so is their country - the sea. One ship is very much like another, and the sea is always the same. In the immutability of their surroundings the foreign shores, the foreign faces, the changing immensity of life, the glide past, veiled not by a sense of mystery but by a slightly disdainful ignorance; for there is nothing mysterious to a seaman unless it be the sea itself, which is the mistress of his existence and as inscrutable as Destiny."