Each machine has been hand finished with Danish Oil and Urethane for protection. Wood has been chosen due to its marvelous engineering properties, primary amongst these is its ability to absorb sound and vibration enhancing the WaterRower's quietness and smoothness of use. Ash, like all woods used in WaterRower construction, is a premium hardwood with incredible longevity and dimensional stability. For reasons of ecology, all our woods are harvested from replenishable forests.
Rowing machines were first used in Archaic Greece. Chabrias, an Athenian military general in 4th Century B.C., invented wooden rowing simulators for his inexperienced oarsmen. This enabled them to learn technique and timing before stepping foot on actual water crafts. And it must have worked — Chabrias successfully led numerous naval attacks against the Spartans.
Rowing is a cyclic (or intermittent) form of propulsion such that in the quasi-steady state the motion of the system (the system comprising the rower, the oars, and the boat), is repeated regularly. In order to maintain the steady-state propulsion of the system without either accelerating or decelerating the system, the sum of all the external forces on the system, averaged over the cycle, must be zero. Thus, the average drag (retarding) force on the system must equal the average propulsion force on the system. The drag forces consist of aerodynamic drag on the superstructure of the system (components of the boat situated above the waterline), as well as the hydrodynamic drag on the submerged portion of the system. The propulsion forces are the forward reaction of the water on the oars while in the water. Note also that the oar can be used to provide a drag force (a force acting against the forward motion) when the system is brought to rest.
Ergometer rowing machines (colloquially ergs or ergo) simulate the rowing action and provide a means of training on land when waterborne training is restricted, and of measuring rowing fitness. Ergometers do not simulate the lateral balance challenges, the exact resistance of water, or the exact motions of true rowing including the sweep of the oar handles. For that reason ergometer scores are generally not used as the sole selection criterion for crews (colloquially "ergs don't float"), and technique training is limited to the basic body position and movements. However, this action can still allow a comparable workout to those experienced on the water.

Water rowers feature a tank that is actually filled with water as a means for resistance. As you increase the pace of rowing, the resistance naturally increases as well. This means that you can set your own pace and resistance in a single motion. The same is true for air rowers. Air rowers use a fan or flywheel to create resistance, and you have control over the intensity of the workout due to the fact that the air resistance depends on your pace. Most water and air rowers come equipped with -- or at least have as an option -- monitors that track various functions such as distance, strokes, strokes per minute and calories burned.
Although some rowing machines are made of space-age, super-sweat-resistant metals, you still want to wipe off the equipment after a sweaty workout.  These machines are usually constructed with a lot of various materials and salty sweat can be very corrosive.  Keeping your rowing machine clean can go a long way toward extending its life, and its appearance.
Motion of the water is different than the motion of the wave. Water at each location moves in a circular path, but the motions at different locations are “out of phase”, which means that when water at the left of the diagram is moving to the right, water a quarter of a wavelength to the right is moving down, and water next to it is moving to the left, and next to it is moving up, etc. The overall effect is a an “apparent” wave moving to the right. Thus, the velocity (speed) of a wave is not at all the same as the velocity of the water.
Some rowing enthusiasts claim that the disproportionate number of tall rowers is simply due to the unfair advantage that tall rowers have on the ergometer. This is due to the ergometer's inability to properly simulate the larger rowers drag on a boat due to weight. Since the ergometer is used to assess potential rowers, results on the ergometer machine play a large role in a rower's career success. Thus, many erg scores are weight-adjusted, as heavyweights typically find it easier to get better erg scores. Also, since crew selection has favored tall rowers long before the advent of the ergometer,[46][47] and bigger, taller crews are almost universally faster than smaller, shorter crews on the water, being tall is a definite advantage ultimately having little to do with the ergometer.
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 Classic rowing machine. Using the same principles that govern the dynamics of a boat in water, the WaterRower Classic 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 Classic is remarkably smooth and fluid.
Outside of resistance type, we found the number-one arbiter of ride feel to be cord quality. Water ergometers tend to employ nylon cords, while air ergometers feature metal chains — a durability factor we anticipated would result in our favoring air. But while all three water rowers aced our expectation of smooth, high-tension strokes, perfecting the chain seems to be more difficult: Some tug with just a slight rumble, others feature bouncy, grinding chains that are incredibly loud, something akin to angry snoring. As for nylon, the best wind and unwind like elastic silk — no slack, no sound, no catching, just perfectly even tension throughout the stroke.