Sailing Boat Low-poly 3D model

A sailboat or sailing boat is a boat propelled partly or entirely by sails and is smaller than a sailing ship. Distinctions in what constitutes a sailing boat and ship vary by region and maritimTraditional sailboats are monohulls, but multi-hull catamarans and trimarans are gaining popularity. Monohull boats generally rely on ballast for stability and usually are displacement hulls. This stabilizing ballast can, in boats designed for racing, be as much as 50% of the weight of the boat, but is generally around 30%. It creates two problems; one, it gives the monohull tremendous inertia, making it less maneuverable and reducing its acceleration. Secondly, unless it has been built with buoyant foam or air tanks, if a monohull fills with water, it will sink.

Multihulls rely on the geometry and the broad stance of their multiple hulls for their stability, eschewing any form of ballast. Some multihulls are designed to be as light-weight as possible while still maintaining structural integrity. They can be built with foam-filled flotation chambers and some modern trimarans are rated as unsinkable, meaning that, should every crew compartment be completely filled with water, the hull itself has sufficient buoyancy to remain afloat.

A multihull optimized for light weight (at the expense of cruising amenities and storage for food and other supplies), combined with the absence of ballast can result in performance gains in terms of acceleration, top speed, and manoeuvrability.

The lack of ballast makes it much easier to get a lightweight multihull on plane, reducing its wetted surface area and thus its drag. Reduced overall weight means a reduced draft, with a much reduced underwater profile. This, in turn, results directly in reduced wetted surface area and drag. Without a ballast keel, multihulls can go in shallow waters where monohulls can not.

There are trade-offs, however, in multihull design. A well designed ballasted boat can recover from a capsize, even from turning over completely. Righting a multihull that has gotten upside down is difficult in any case and impossible without help unless the boat is small or carries special equipment for the purpose. Multihulls often prove more difficult to tack, since the reduced weight leads directly to reduced momentum, causing multihulls to more quickly lose speed when headed into the wind. Also, structural integrity is much easier to achieve in a one piece monohull than in a two or three piece multihull whose connecting structure must be substantial and well connected to the hulls.

All these hull types may also be manufactured as, or outfitted with, hydrofoils.e culture.