This type of machine provides a smooth action with little wear and tear to the mechanism, and the flywheel itself could help to keep you cool as you work out. It's worth noting that although water rowers aim for a realistic rowing feel, competitive rowers often use air rowers for land training. They tend to be less expensive than water-powered rowing machines, as well.
Do you need a machine that folds up? If you've decided to avoid a water rower for space reasons, you may prefer a model that folds up for storage. Even better, some rowing machines have wheels fitted to them, so that once it's folded up, you can steer it to a storage space out of the way. You can find a foldable design in many magnetic and some air rowers.
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.