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.
If you’re interested in using a rowing machine for focused training — whether for outdoor rowing, an indoor competition, or as part of a larger fitness program — you’ll want air resistance. If you’re drawn to rowers for the enjoyability (alongside the full-body, cardio-plus-strength training efficacy) of a rowing workout, consider a machine with water resistance.
* While there is nothing to adjust from row to row on the WaterRower, it is possible to increase or decrease the level of resistance by changing how much water you put in the drum. The monitor is pre-calibrated to match 17 liters of water, but you can change that if you want. More than 17 liters = more resistance, up to the max fill line. This is not something you'll want to change frequently, it's more of a set-it-and-forget-it thing.