“There are a lot of ways to move a boat down a race course in a fast manner,” says NBP announcer David Wyant. The seats are on tracks that can slide back and forth.

1. At the start of a stroke, the athlete sits forward with knees bent, arms forward and oar blades behind her. Pushing with her legs, she pulls the blades through the water and lifts them out as cleanly as possible.

To get a sense of different stroke styles, keep an eye on the athletes’ torsos.

2. “At the finish of the stroke, some crews will really try to throw their backs into it and finish it off almost lying back,” explains Wyant. “Other crews will almost be sitting straight up and down, perpendicular to the boat.”

3. As the rower slides forward again, she bends her knees and pushes the oars backwards in preparation for another stroke. “That transition is the most important part,” says Bryan Volpenhein, a senior men’s coach for Team U.S.A. “You have all this weight coming forward, but the boat’s going the other direction. That’s the athletic part; you have to be skilled at changing direction and driving the boat the other way.”

4. Sometimes the oar blade catches the water wrong, flubbing the stroke—in rowing parlance, “to catch crab.” The oar may be wrenched from the rower’s hand, and, in extreme cases, as the blade is carried backwards by the boat’s momentum, the handle shoots forward and slams into the rower’s chest or face.