Moment arm
From KayakWiki
A moment arm is like the length of the lever. If you put a torque wrench that is 18 inches long on a bolt and you push on the end of the wrench, the length of the moment arm is 18 inches. The amount of torque will be the length of the moment arm times the amount of force you are pushing with.
In a kayak moment arms are used to determine stability and other performance characteristics.
