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.
As I mentioned, the rowing experience with the WaterRower is amazing. I bought the rower for myself, but my wife was curious and decided to try it out. She loves it, and now rows almost daily. We have a treadmill that neither of us has used since we started rowing - the WaterRower is a much better workout and much more enjoyable at the same time. It's easy to adjust the intensity, pace and duration of your exercise. There is nothing to change on the rower (* see note below), you just row harder or faster, adjust how far you lean forward and back during your stroke. The WaterRower will keep up with you as your fitness increases, all you need to do is keep throwing more and more at it.