What do “beam” and “rocker” mean?
A. The beam of a boat is its width and, generally, the wider the beam the more stable the kayak. To understand rocker, imagine looking at the side profile of a kayak the more it looks like a banana the more rocker it has and the easier it will be to turn (and, conversely, the greater challenge it will be to paddle straight). On a river with lots of obstacles, you would want a boat with more rocker for quicker turns. On the ocean and for long straight paddles, a kayak with less rocker is preferable.