Rowers may take part in the sport for their leisure or they may row competitively. There are different types of competition in the sport of rowing. In the U.S. all types of races are referred to as regattas whereas this term is only used in the UK for head-to-head or multi-lane races (such as those that take place at Dorney Lake), which generally take place in the summer season. Time trials occur in the UK during the winter, and are referred to as Head races. In the US, head races (usually about 5k, depending on the body of water) are rowed in the fall, while 2k sprint races are rowed in the spring and summer.
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.