134 x the square.

Semi displacement catamaran hull design. For long-range power boat design based on a displacement hull. 153m Pilothouse Cruising Yacht. Many of the cats can use either displacement or planing hulls depending on the speed to be optimized.

Catamaran aft floats form a tunnel there between. Catamarans save on weight because the multihull design eliminates. Few Catamarans are actually planning vessels.

The ballasted displacement hulls deep draft creates a very low center of gravity and results in a lot of hull below the waterline which makes the boat much less susceptible to the wind. 148m Planing Power Cat. 146m Composite planing power cat.

Catamaran hulls can be designed as planing or displacement hulls but they are not slowed nearly as much by the drag barrier. Catamarans are also very light which further reduces drag and displacement. Catamarans reduce drag by making use of a very thin and pointed hull design.

Fore outer boards and deck decks smoothly change over into aft outer boards of said floats and deck. Most are semi-displacement boats like most modern IMSIRC derived monohulls. This book was considered by many as the bible at the time and still is by some although he was not a fan of the trend in the 1980s to try and increase cruising speeds by moving towards a semi-displacement hull form even if Arthur DeFever was one of those involved.

Hullforms may be divided broadly into 3 categories. A well-designed displacement hull is a lot easier to keep pointed into the wind at low speed than a planing hull which is good because low speed is all that this genre is capable of. They know what works for a single hull boat and the cats they design are even better boats.