The ships had one large square sail. In bad weather it was lowered over the ship and fastened down like a tent to protect the men inside.	Viking ships were called Longships.	A big longship would be about 30m long and could travel at up to 32km per hour. It would have about 32 oars.
The Vikings carved the prow of their ships into elaborate shapes such as the head of a dragon or another animal.		The gaps between the planks of the ships were made waterproof by filling them with sheep's wool dipped in tar.
The ships had names which reflected the shape of their prows, like "Long Serpent", "Snake of the Sea" and "Horse of the Home of Ice".	When there was no wind oars were used to row the ship.	The Viking ships were among the first to have a keel. This helped them to cut through the water very fast and made them very stable in rough weather.