Yes! The mother of indoor rowing competitions is the CRASH-B Sprints, held annually in Boston. The Charles River All-Star Has-Beens started when the U.S. boycotted the Olympics in 1980 — during the same era that Concept 2 launched their Model A; necessity met opportunity. CRASH-B is still held with aplomb and doesn’t require any special qualification of its applicants.
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.