The "fat cousin"
drill is a drill done by rowers in order to improve their timing and
balance. Rowers sit at the finish, legs down, laid back, with their arms close to their body. Their blades are squared and buried. On the
coxswain, bowman or
stroke's call, the rowers will lift their blade out of the water,
feather, and recover. The drill ends when all rowers make a fake catch with the water and snap their blades down without squaring them up first.
If all the rowers do this together, they'll make a loud "plop" noise when they make the fake catch. This indicates a successful completion of the drill, and is the sound your fat cousin makes when he jumps off the diving board, thus explaining its name. There is a variation of the fat cousin, called the skinny cousin, where the rowers actually square their blades and make a regular catch. Because they end squared and buried, this makes a much softer sound.
This drill can be one of the most annoying and frustrating drills in all of rowing if done poorly, but it is a great confidence booster if done correctly. If just one of the rowers is off with his timing or balance, the entire boat will be affected. The goal of the fat cousin drill is to get one strong splash at the end. It sounds easy, but rowers must move their arms and back away together, come up to the slide together, and lift their arms together -- all within millimeters of each other. Fat cousin drills are infamous for isolating people with timing and balance issues. Though this causes a lot of frustration among the other people in the boat who are doing things correctly, this forces people to clean up those issues. Since the things practiced in this drill are so important in rowing, the fat cousin is one of the most beneficial drills a crew can do.