"The General Prologue" describes the Sailor in terms of his hometown, horse, clothes, weapon, face, moral qualities, fighting prowess, seaman's skills, ability to survive, skill in astronomy and the name of his ship.
The narrator says he comes from the west, perhaps Dartmouth, a famous shipping town full of skilled sailors. The Sailor rides an inelegant carthorse and wears a garment made of wool, not costly silks, that hung to his knee rather than being long. This bespeaks the Sailor's practicality and may also speak his economic circumstances as being not the best.
His weapon is hung by a cord, not leather, looped over his neck and slung under his arm to hang at his side, while his face is said to be burnt brown by the sun. The narrator then sarcastically says he is a fine person morally who drinks wine while the trader sleeps, implying that the Sailor is stealing the wine.
This is reinforced by the statement that he doesn't have much of an active conscience and that in battle he always slays his opponent and sends him to waste in the sea. The narrator then redeems the Sailor by saying that of his trade he is a master, being great with all sea craft, with a reputation from England to Carthage in the Mediterranean.
Later he also adds that his skill extends to astronomy and to being able to read the skies over all lands. The narrator wraps up by saying that the sailor is a hearty man who has survived many vicious storms and sails on a ship called the Madeleine.