How do outriggers make narrow Pacific Island canoes more stable?

Pacific Island canoes are typically designed with narrow hulls, which makes them inherently unstable in open water. To counteract this, they are fitted with outrigged floats on one or both sides of the main hull.1

These outriggers provide the necessary lateral support to prevent the narrow craft from capsizing, effectively increasing the boat's stability while maintaining the speed and efficiency of a slender design. In some cases, this stability is achieved instead by linking two canoes of equal size side by side, a configuration known as a catamaran. These structural adaptations allow the vessels to safely navigate the open sea, where they have historically been used for transport and long-distance voyaging.12