Trimaran sailplan. They contribute to drag when heavily immersed, and their level of immersion indicates when to reef. Two types of trimaran exist: the regular trimaran and the open trimaran, which features a trampoline between the hulls instead of plating. Trimarans have a number of advantages over comparable monohulls (conventional, single-hulled sailboats). Given two boats of the same length, the trimaran has a shallower draft, a wider beam, less wetted area, and is able to fly more sail area. In addition, because of the righting moment provided by the wide beam, trimarans do not need the weighted keel that is required
Pontoon effect side than the center of buoyancy can go. At this point, the righting force will disappear, replaced by a turning moment in the opposite direction. This can capsize the vessel at the point at which one pontoon is completely submerged. When using twin lateral pontoons, each pontoon should have enough buoyancy to bear the load of the entire vessel on its own. If the vessel is so heavy that either pontoon is mostly submerged when no lateral force is applied, it will be vulnerable to the pontoon effect. If sufficient lateral force arises (such as wind or shifting load), the