A monohull's a type of boat having only one hull, unlike multihulled boats which can have two or more individual hulls connected to one another. Fundamental Concept Among the earliest hulls were simple logs, but these were generally unstable and tended to roll over easily. Hollowing out the logs into a dugout canoe doesn't help much unless the hollow section penetrates below the log's center of buoyancy, then a load carried low in the cavity actually stabilizes the craft. Adding weight or ballas… (More on Monohull)