A longboat is a large boat powered by multiple oars and carried on a ship (especially sailed merchant ships). It is generally used for landing in waters too shallow for the ship. It also allowed the Vikings to sail on rivers. They were also very convenient because they were easily lifted. The Vikings would carry their boats from river to river. They made it all the way to Constantinople, both to trade and to attack.
The longboat differed from the gig in that it was generally wider, where the oarsman rowed a single oar sitting either side by side for the larger craft, or in alternating seats. The longboat was generally more sea kindly than the gig and in the event of an abandonment of the ship could hold a large number of the crew.
See also: longships, which are Viking craft sometimes referred to as longboats, but which are not boats in this sense because they have sails.
