The difference between the 3 types of rowing machine is the resistance, below is a brief explanation of each resistance type Air rower - air rowing machines have a fan at the front that spins as you row. The fan creates drag with the air and this is the resistance you feel when rowing. One of the great advantages of air rowers is the rowing motion remains smooth throughout the workout, plus the breeze created from the fans helps keep you cool. Water Rowers - water rowing machines use a water as the drag, inside the water tank is a fan that spins in the water creating a resistance when you row. Water rowers are smooth in motion similar to air rowers but are much quieter; in fact the noise created from a water rower can be quite calming. Magnetic rowers - magnetic rowing machines use a magnet as resistance but do not feel as smooth as water and air rowers.