The standard length races for the Olympics and the World Rowing Championships is 2 kilometres (1.24 mi) long; 1.5 kilometres (0.93 mi) - 2 kilometres (1.24 mi) for US high school races on the east coast; and 1,000 m for masters rowers (rowers older than 27). However the race distance can and does vary from dashes or sprints, which may be 500 metres (1,640 ft) long, to races of marathon or ultra-marathon length races such as the Tour du Léman in Geneva, Switzerland which is 160 kilometres (99 mi), and the 2 day, 185-kilometre (115 mi) Corvallis to Portland Regatta held in Oregon, USA. In the UK, regattas are generally between 500 metres (1,640 ft) and 2 kilometres (1.24 mi) long.
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.