Cardiovascular training involves any activity that requires the use of the large muscle groups of the body in a regular and uninterrupted manner. Rowing is one of the few non-weight bearing sports that exercises all the major muscle groups. In addition, the consistent and all encompassing activity associated with rowing, combined with being outdoors on the water, has an unparalleled impact on reducing stress.2
Founded in 1818, Leander Club is the world's oldest public rowing club. The second oldest club which still exists is the Der Hamburger und Germania Ruder Club which was founded 1836 and marked the beginning of rowing as an organized sport in Germany. During the 19th century, as in England, wager matches in North America between professionals became very popular attracting vast crowds. Narragansett Boat Club was founded in 1838 exclusively for rowing. During an 1837 parade in Providence, R.I, a group of boatmen were pulling a longboat on wheels, which carried the oldest living survivor of the 1772 Gaspee Raid. They boasted to the crowd that they were the fastest rowing crew on the Bay. A group of Providence locals took issue with this and challenged them to race, which the Providence group summarily won. The six-man core of that group went on the following year to found NBC in 1838. Detroit Boat Club was founded in 1839 and is the second oldest continuously-operated rowing club in the U.S. In 1843, the first American college rowing club was formed at Yale University. The Harvard–Yale Regatta is the oldest intercollegiate sporting event in the United States,http://rowinghistory.net/Time%20Line/TL%20-1849images.htm having been contested every year since 1852 (excepting interruptions for wars).
The rowing machine itself is unlike any other on the market with its patented water filled flywheel. It is hard to exactly copy the action of a scull on the water, but the mechanics of the flywheel spinning in water comes in a close second on dry land. The fact that the water is 800 times denser than air means that there is no need for any extra resistance or dampening that you will find in normal air rowers. The faster you pull, the more resistance is generated giving it infinite variability. However, if you want to be able to practice rowing with a faster stroke, you will have to reduce the amount of water in the tank unlike an air rower where you just have to adjust the baffle.