Rowing, often referred to as crew in the United States, is a sport whose origins reach back to Ancient Egyptian times. It involves propelling a boat (racing shell) on water using oars. By pushing against the water with an oar, a force is generated to move the boat. The sport can be either recreational for enjoyment or fitness, or competitive, when athletes race against each other in boats. There are a number of different boat classes in which athletes compete, ranging from an individual shell (called a single scull) to an eight-person shell with coxswain (called a coxed eight).
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.