There is much to love about the WaterRower--and I do love it--but I would echo others' comments that although the seat rolls solidly and smoothly on the wood rails, the seat itself is very hard (I use a gel seat pad I bought for my hard fiberglass kayak seat), and the footpads are in need up rethinking and upgrading--the cheap plastic doesn't let you row in socks or barefoot and is not really worthy of a machine that is otherwise a stunning piece of engineering and a beautiful one as well. As one other person noted about his machine, my machine made a clicking noise on the return stroke, so I had to adjust the wheel underneath the top rail that connects to the footpad and pull it away gently from where it was rubbing against another component. Also, be warned: the instruction booklet is in the DVD case. I did not see the little sticker on the case telling me that, thinking I'd wait to watch the DVD until after I'd assembled it. But WaterRower has a copy of the assembly instructions on their website, along with a video (I found the written ones better and easier to follow), so I was able to assemble it with no difficulty.
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.
Noise level is another large factor that tips the scale more towards water rowers. Air rowers make a fairly loud “whooshing” noise every stroke, which makes them bad for people who like watching TV, have sleeping children, live in apartments, or like working out early in the AM. Water rowers do make some noise but the splashing of water in the tank is a lot quieter and more soothing than the fan noise produced by air rowers.
Rowing has long been recognized as the perfect aerobic pursuit, with naturally smooth and flowing movements that don't tax the joints but do boost the heart rate. Now you can take your rowing experience to the next level with the WaterRower Natural rowing machine. Using the same principles that govern the dynamics of a boat in water, the WaterRower Natural is outfitted with a "water flywheel" that consists of two paddles in an enclosed tank of water that provide smooth, quiet resistance, just like the paddles in an actual body of water. As a result, the machine has no moving parts that can wear out over time (even the recoil belt and pulleys don't require lubricating or maintaining). More significantly, the water tank and flywheel create a self-regulating resistance system that eliminates the need for a motor. As with real rowing, when you paddle faster, the increased drag provides more resistance. When you paddle slower, the resistance is less intense. The only limit to how fast you can row is your strength and your ability to overcome drag. And unlike conventional rowing machines, which tend to be jerky and jarring, the WaterRower Natural is remarkably smooth and fluid.