If the machine is to be housed on a wooden floor you will need a mat beneath to reduce vibration and also noise. If space is tight, the hydraulic options are usually the smallest. It's also worth checking your floor can take the weight if you're going for one of the bigger, heavier models. For most, this shouldn't be a problem, if you have any doubts get a surveyor to check as it could be a very expensive mistake!
At the catch the rower places the blade in the water and applies pressure to the oar by pushing the seat toward the bow of the boat by extending the legs, thus pushing the boat through the water. The point of placement of the blade in the water is a relatively fixed point about which the oar serves as a lever to propel the boat. As the rower's legs approach full extension, the rower pivots the torso toward the bow of the boat and then finally pulls the arms towards his or her chest. The hands meet the chest right above the diaphragm.
The rowing machine itself is unlike any other on the market with its patented water filled flywheel. It is hard to exactly copy the action of a scull on the water, but the mechanics of the flywheel spinning in water comes in a close second on dry land. The fact that the water is 800 times denser than air means that there is no need for any extra resistance or dampening that you will find in normal air rowers. The faster you pull, the more resistance is generated giving it infinite variability. However, if you want to be able to practice rowing with a faster stroke, you will have to reduce the amount of water in the tank unlike an air rower where you just have to adjust the baffle.