Could anyone tell you the difference between a concave bottom kayak and a keel type bottom kayak?

A concave bottom kayak features a hull that curves inward, allowing for greater maneuverability and stability, making it ideal for rivers and rough waters. In contrast, a keel type bottom kayak has a pronounced ridge running along the center, which enhances tracking and speed in calm waters. The choice between the two depends on the paddler's intended use—whether they prioritize agility or straight-line performance.