Don't know why, perhaps due to rising demand and production bandwidth, but be forewarned quality control is an issue. Assembly is easy enough, though have gap where back separator does not fit snugly after tightening nuts as firm as they will go (see pic). No water level sticker on tank received, so had to measure water manually according to calculations (4 gallons). Siphon was not air tight (even though release valve closed firmly), so had to manually pump instead of siphon. S4 monitor only flashes, not working as of yet and now have to take a apart top of unit to figure out why, currently not resolved after verifying connections and looking at simple solutions on website.
This popular rowing machine utilizes magnetic resistance for a quiet, and very smooth workout. The Velocity Exercise CHR-2001 also features a programmable computer with 12 programs that will keep your exercising varied and challenging for years. The computer also provides data on distance, time, calories burned, pulse rate, strokes per minute, and stroke count. Additionally, the tension resistance is electronically controlled via the computer.  This electronic resistance control feature puts the CHR-2001 ahead of other magnetic rowers that tend to use knobs.
 The amount of water in the tank simulates the weight of the boat and crew, the more water in the tank the heavier the boat and crew. The standard Calibration Level is Level 17. If the user is lighter in weight, Level 15-16 can be used. If the user is heavier in weight, level 18-19 can be used. The maximum level to fill the tank is Level 19. DO NOT fill above the maximum level – this could void the warranty.

The WaterRower Club is handcrafted from solid Ash wood, finished with a black and rose stain and 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
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.
As far as “racing”, I said an air rowing machine is better because the Concept2 is the only model used for indoor rowing competitions, setting world records, and entering your actual scores online. It is because their monitor can calculate the drag factor of the flywheel in real time and accurately calculate distance and time. Small changes such as dust build up, air temperature, and humidity will not change the times between different machines because the drag factor is calculated every stroke.

The dense resistance of water creates substantial drag, but on the WaterRower models, this is perfectly tempered by a whippy cord. It coils and recoils with such steady speed that one tester noted how the Classic “eats the rope back up on recovery.” This smooth agility helps balance out the impact of encountering slow water at the start of every stroke.
Both the air rower and water rower machines are very popular choices of rowing equipment, particularly the former type. They have been around in the 80s, and many consumers and those that have tried them in gyms consider the equipment to be the best type ever. These air resistance equipment, often regarded as Ergometers, is the standard base model for indoor rowing sport.
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.
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.