Types of Hull
Power boat hulls are divided into three main types:
- Displacement
- Semi-displacement
- Planing hulls
Hull types can have a variety of sub-types, closer to each end of the scale. When choosing your hull always consider your intended usage and your budget.
The size of your power boat will also be a factor in your choice of hull type. If you are considering a large power boat you will be less likely to choose a Full Planing hull. Large Fast Planing hulls require expensive engines, use large amounts of fuel and operating costs are high.
We've put together this list of the different types of power boat hulls available:
Heavy Displacement
Heavy Displacement Hulls include such craft as tugs and deep sea trawlers, with the stern rising above waterline. The Heavy Displacement hull has to be able to carry great loads and in the case of tugs, be able to get a grip on the water in order to do its job properly. The hull speed of this type of vessel is generally less than that of other types.
Medium Displacement
This type of hull includes most regular work boats, general fishing boats and the pleasure boats. For higher speeds consider Semi Displacement or Planing hulls.
One important factor to consider is that Displacement and Semi Displacement hulls are generally considered better Sea Boats and are more suitable for offshore cruising than the Planing Hull.
Semi Displacement or Semi Planing Hulls
These hulls fit in between the Displacement and the Planing hull types. The stern of the Semi Displacement hull is lower and designed to be always below the water. As with Displacement hulls, Semi Displacement hulls can be driven harder, but at the expense of greater fuel consumption and again the stern will tend to dig in at higher speeds. Choose this type of hull when planning to undertake extended cruising - cruising that regularly involves cruising distances of over 100 miles.
Planing Hulls
Planing hulls are very popular, they make great pleasure boats if you are prepared to install sufficient power and pay the larger fuel bills. Planing hulls do not like being operated at low speeds. They throw a most unfriendly bow wave. Planing hulls are not the best of sea boats especially in severe conditions.
Round Bilge
Hulls that are intended for Passage making will most likely be of the round bilge hull form. It is possible to design a Semi Displacement round bilge or round chine hull but the type is more suited to the chine hull configuration. Round bilge can be used for any displacement type hull especially those that are to be used for long distance voyaging.
Radius Chine Building Techniques
These boats are easy to build and exhibit all of the advantages of both chine and round bilge hull forms. These radius chine hulls represent a new development that has been made possible by the technology offered by modern computer assisted yacht design. These soft chine hulls have the capacity to offer the soft ride that we have often desired in a round bilge or chine hull form, but seldom achieved.
Power Catamarans
These boats are becoming increasingly popular and come in a variety of hull configurations. It is possible to design Displacement, Semi Displacement and Planing hulls to be used with the catamaran concept. Semi Displacement Power Catamarans offer comfortable, roomy and economical cruising powerboats.