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.
The main advantages of the water rower are that it has quiet operation; there is only little maintenance to do, the water only needs to be changed occasionally; many users love the whooshing sound of water in the tank; and its consistently smooth resistance at every stroke. Two disadvantages of this machine are it costs a lot than the air rower; and it tends to be larger in size compared to the other rowing machines.
There are various air rower or water rower techniques, but the most basic one is by starting at the back stroke, the knees should almost be completely straight prior to squeezing the shoulder blades together. Then you pull its handle to the sternum. The back of your body should naturally stay in its arched position when doing the whole movement. Do not forget to take a record of the distance you have made after every session. Some people even take it as far as uploading their results online and see how they are ranked from other people who are also doing the same. You clean learn more about rowing machine technique on this page.
The reason I'm writing now, two years after purchase, is, I broke one of the wheels. I proceeded to order the wrong replacement, so I emailed them pictures to ask for the right parts. They wrote back asking for the serial number to get the right unit AND to see if it was under warranty. (Hadn't even occurred to me.) Turns out it was, they're sending me the wheels, they're refunding me for the wrong part, AND included a link for the Puri-Tabs which I didn't know they provide for the life of the ROWER! They're also replacing all eight wheels even though there's only one broken one.
Other details include dual rails with four corner wheels that increase seat stability and reduce the amount of sweat buildup; a frame that flips upright for handy storage; and a weight capacity of up to 1,000 pounds. The WaterRower Natural measures 84 by 21 by 22 inches (W x H x D), weighs 117 pounds (with water), and carries a one-year warranty on the frame and components (WaterRower will upgrade the warranty to five years on the frame and three years on the components with the completion of a registration form).