The earliest discovered longship built from traces back to BC. The ship was recovered from the Hjortspring bog in southern Denmark. Called the Hjortspring boat it was made of planks of wood sewn together with cord. The spaces between planks were filled with resin. The ship was about 59 feet (18 meters) long and was a very light and flexible design. It had a double bow and stern that looked like a bird's beak. The ship had places for 20 men to row and had a steering oar at both ends. A replica of this design was built and tested. It was very , fast and . In calm waters it averaged 6 knots (about 7 miles per hour) in speed. 