The gondola is a traditional, flat-bottomed Venetian rowing boat, well suited to the conditions of the Venetian lagoon. It is typically propelled by a gondolier, who uses a rowing oar, which is not fastened to the hull, in a sculling manner, and also acts as the rudder. The uniqueness of the gondola includes its being asymmetrical along the length, making the single-oar propulsion more efficient. For centuries, the gondola was a major means of transportation and the most common watercraft within Venice. In modern times, the boats still do have a role in public transport in the city, serving as traghetti (small ferries) over the Grand Canal operated by two oarsmen.

Source: Wikipedia