are long, wider in the middle and narrow at both tips. A wider middle (beam) adds stability. A Keel-like shape at the tips helps to slice through water and contributes to tracking (the ability to follow a straight course) and stability. Wider kayaks are more stable (less likely to roll). The overall shape of the middle and the way the kayak curves out of the water also effects stability. A hull shape that flairs toward the water will increase stability. A rigid angled hull (hard chine) may improve turning performance and add primary stability (reduce side-to-side rocking) but will make secondary stability unpredictable by creating a point of no return. A rounder shape (soft chine) will lesson the chance of a surprise roll but will reduce primary stability allowing more side-to-side rocking. The use of a skeg or rudder adds control and stability to a kayak.