multihulls and catamarans

A multihull, just as any other type of boat, presents a series of compromises,and this applies to overall hull, deck andconfiguration as well. Concessions often have to be made because of space, performance or construction costs. In addition, the intended usage will be a significant factor in determining the shape and size of the vessel.

What´s the difference between a catamaran and a multuhull ?

Successful cruising designs will balance all parameters and only you, as a sailor, will know which type of catamaran will be suitable for your needs.A monohull’s characteristics, largely determined by the beam-to-length ratio of the hull and its displacement, will vary very little from another ballasted boat, as there is only so much volume you can fit into a single hull. This will establish the amount of accommodations, which will not greatly differ from one monohull to another, setting a stark contrast to a catamaran, where intended parameters vary so much more.Basically, we can break down the major design considerations into: overall configuration, hull shape, underwater appendages, rig type and construction. Let’s look at each of them in detail and see how they affect the dynamics and design of a multihull.

How each detail affect the dynamics and design of a multihull:

If one thinks of an open bridgedeck-type of catamaran, images of Hobie Cats on one end of the spectrum, and giant-open ocean racing multihulls on the extreme end, come to mind. They have no fixed coachhouse roof and some of them, especially the small beach cats, only have nets strung between the hulls. Larger examples have partial composite platforms, which stiffen the structure and allow for cockpit seats and helm stations.Since without a solid coachhouse there is less boat to build, these multihulls will be generally lighter and have better aerodynamic properties than full bridgedeck-type cats.Although few manufacturers and designers have attempted to build open bridgedeck catamarans for cruising, only the most die-hard campers will find them useful for liveaboard applications. Typical examples are the older MacGregor 36, Stiletto 27 and 30, the French KL27 and Corneel designs,which could be sailed hard by lifting a hull (something that you try to avoid when cruising with a fully decked-out boat).Some of these vessels even featured a tiny removable doghouse which provided some shelter for the crew.

The advantages of  small sporty vessels:

On smaller open bridgedeck multihulls the only living quarters are found in the confines of the hulls. Even on larger types, they are cramped and not conducive to long-term cruising.The advantages of these sporty vessels,especially in sizes below 30 feet, is their lower cost, trailerability and lively performance.However, attention has to be paid that they not be overloaded or else one could easily turn a cat into a dog.A large exception to the class 1 type of configuration is found in sizes above 30 feet, which could be considered as class 2.Manufacturers such as Maine Cat and a few other custom multihulls such as the Shuttleworth successfully combine an opendeck plan with a certain degree of cruising comfort. In order to provide some shelter for the crew, large semi-rigid biminis are erected. Not only are these afterthoughts unsightly and do no justice to the beauty of these boats, but they also add a considerable amount of drag, contradicting the nature of these athletic multihulls.

Large charter boats or “Day Boats,” as they are called, also utilize the open bridgedeck layout to maximize cockpit space. These machines can entertain up to 80 passengers and are found in holiday resorts around the world. Correctly managed and marketed,they are big moneymakers and are considered the workhorses of the sea.You can get catamarans for sale in our site.