There are a lot of boats on the market. When shopping for a boat you'll quickly become familiar with the basic boat design terminology. The length of a kayak effects its speed and maneuverability. The more volume a boat has the more buoyant it is. The boat's rocker refers to the upward curve of the bottom of a boat.
Less rocker provides better tracking or enhances the boat's ability to move in a straight line.
More rocker will help the boat to ride over waves. A wide boat adds stability. Beginner boats are great to have around. They're fun for the kids and friends to play around on. But they don't perform well.