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.
In addition to the high levels of fitness attained, rowing is an intense calorie-burning exercise. The late Dr. Fritz Hagerman, Professor of biomedical science and a leading researcher in rowing physiology, determined that "...you burn more calories in rowing than any other activity. Cross-country skiing comes closest. At standard submaximal levels of exercise, rowing will burn calories at a rate 10-12% higher than running, and 15-20% higher than cycling."  Although rowers with less ability and training will burn fewer calories, the ergometer is an excellent tool for use in a weight-loss program.
1.) I keep reading about cracks and leaks that develop in the water tank. WaterRower even offers a tank repair kit for this very issue. It seems to me that this is a design flaw that they refuse to address, instead offering a fix for when it eventually occurs. Have you seen these tanks to eventually leak? I’m surprised they haven’t tried a one-piece tank.
John Duke, creator of the WaterRower, was inspired to try his hand at invention while working at a subsidiary for U.S. Steel. He wanted to make an indoor machine that felt as much like real rowing as possible, with a focus on aesthetics. It took him two years to get the design right, moving past failed ideas such as a flipper in the tank instead of a clutch. What began as a series of doodles at his desk turned into a sculptural piece of exercise equipment that upends expectations in two ways: by bringing water indoors, and by looking elegant and artful when stored.
In a 1988 US patent (US4772013A), Elliot Tarlow discloses another non-elastic chain/cable take-up and handle return strategy. Described and depicted is a continuous chain/cable loop that passes around the flywheel sprocket and around and between fixed pulleys and sprockets positioned fore and aft on the device. The handle is secured in the middle of the exposed upper horizontal section of the chain/cable loop. Although somewhat lacking in aesthetics, the Tarlow device does eliminate the stated disadvantages and defects of the ubiquitous elastic cord handle return. Tarlow further argues that the disclosed method provides an improved replication of rowing because in actual rowing the rower is not assisted by the contraction of a spring or elastic cord during the "recovery" portion of the stroke. The rower must push the oar handle forward against wind and oarlock resistance in preparation for the next stroke. Tarlow asserts that the invention replicates that resistance.
While the rowing machine is an incredibly efficient, full-body workout that allows the athlete to build aerobic endurance and muscular strength at the same time, a lack of proper technique and training is common among gym-goers and can lead to injuries and misuse. So we asked experts from the number one collegiate men’s crew team in the country at the University of California – Berkeley—Head Coach Mike Teti and Associate Head Coach Scott Frandsen—to give you the lowdown on everything you need to know about the rowing machine. Both are Olympic medalists (Teti is both a medalist as an athlete and a coach) who know exactly what it takes, in the gym and on the water, to get in gold medal-winning shape.
Bring the unparalleled full-body workout of on-the-water rowing home with the premium design and feel of the XTERRA Fitness ERG600W Water Rower. The full body rhythmic nature of rowing makes it wonderfully efficient at burning calories while also developing flexibility and strength. Plus, the "zen-like" water movement you hear from the ERG600W multi-bladed impeller can be soothing and meditative. The large and easy to read 5.5" LCD console with height and angle adjustment includes motivating programmable modes to keep you involved, inspired, and reaching your goals.
In 1981, Peter and Richard Dreissigacker, and Jonathan Williams, filed for U.S. patent protection, as joint inventors of a "Stationary Rowing Unit". The patent was granted in 1983 (US4396188A). The first commercial embodiment of the Concept2 "rowing ergometer" (as it came to be known) was the Model A, a fixed-frame sliding-seat design using a bicycle wheel with fins attached for air resistance. The Model B, introduced in 1986, introduced a solid cast flywheel (now enclosed by a cage) and the first digital performance monitor, which proved revolutionary. This machine's capability of accurate calibration combined with easy transportability spawned the sport of competitive indoor rowing, and revolutionised training and selection procedures for watercraft rowing. Later models were the C (1993) and D (2003). 
Unlike its WaterRower Natural cousin, the WaterRower Club is designed for high-traffic areas, such as commercial gyms, studios, and rehabilitation clinics. Its dual black rails have been styled to prevent scuffing, while the other wood components are finished in an attractive rosewood, which is more resistant to soiling than the Natural model. Other details include four corner wheels on the rails 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 Club 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).
The WaterRower Classic is handcrafted from solid American Black Walnut wood, finished with danish oil. The WaterRower's patented WaterFlywheel has been specifically designed to emulate the dynamics of a boat moving though water and is unsurpassed in its simulation of the physical and physiological benefits of rowing. WaterRower will not provide support or documentation for any product transported outside of the original country of purchase
Rowing technique on the erg broadly follows the same pattern as that of a normal rowing stroke on water, but with minor modifications: it is not necessary to "tap down" at the finish, since there are no blades to extract from water; but many who also row on water do this anyway. Also, the rigid, single-piece handle enables neither a sweep nor a sculling stroke. The oar handle during a sweep stroke follows a long arc, while the oar handles during a sculling stroke follow two arcs. The standard handle does neither. But regardless of this, to reduce the chance of injury, an exercise machine should enable a bio-mechanically correct movement of the user. The handle is the interface between the human and the machine, and should adapt to the natural movement of the user, not the user to the machine, as is now the case. During competitions an exaggerated finish is often used, whereby the hands are pulled further up the chest than would be possible on the water, resulting in a steep angulation of the wrists - but even with a normal stroke, stop-action images show wrist angulation at the finish, evidence that the standard rigid, single-piece handle does not allow the user to maintain a bio-mechanically correct alignment of hands, wrists, and forearms in the direction of applied force. On the Concept 2 website "Forum", many regular users of the indoor rower have complained of chronic wrist pain. Some have rigged handgrips with flexible straps to enable their hands, wrists, and forearms to maintain proper alignment, and thereby reduce the possibility of repetitive strain injury. Rowing machine manufacturers have ignored this problem.