From Eaters of the Dead:
These Northmen are by their own accounting the best sailors in the world, and I saw much love of the oceans and waters in their demeanor. Of the ship there is this: it was as long as twenty-five paces, and as broad as eight and a little more than that, and of excellent construction, of oak wood. Its color was black at every place. It was fitted with a square sail of cloth and trimmed with sealskin ropes. The helmsman stood upon a small platform near the stern and worked a rudder attached to the side of the vessel in the Roman fashion. The ship was fitted with benches for oars, but never were the oars employed; rather we progressed by sailing alone. At the head of the ship was the wooden carving of a fierce sea monster, such as appears on some Northmen vessels; also there was a tail at the stern. In water this ship was stable and quite pleasant for traveling, and the confidence of the warriors elevated my spirits.