A "wherry" is a pulling boat that falls somewhere between the needle-thin racing shells and wide, sailboat-like rowboats. Wherries are the ride of choice for rowers who want speed but don't want to confine themselves to the placid rivers that are the natural haunt of a racing shell. The term "wherry" is English in origin, where as early as the 1500's the word was used to describe the swift water taxis in use on the River Thames. An 1878 book, Old and New London, remarks that in 1820 there were 3000 wherries on the Thames. The basic wherry shape---a narrow waterline, flaring sharply above the water to gain stability as the boat heels or is loaded---has not been improved upon in 150 years.