The Basics Of Boat Design

Naval architects reveal design, tooling and material selection guidelines for a new sportfishing powerboat.

"The first thing that has to be defined is how the yacht will be used," says Donald L. Blount and Assoc.'s designer Chris Swanhart. "A fishing yacht, a cruiser or a fast offshore racing boat all have different design requirements."

For starters, a sportfish yacht has unique features that set it apart from other types of vessels. Intended for the pursuit of trophy fish like marlin and tuna, it has an open cockpit large enough to accommodate several crewmembers and a "fighting chair," in which the angler sits. The chair requires extra structural support because it supports the angler's large fishing rod. To spot fish at a distance, the boat also needs a high "flybridge." It requires sufficient power for fast but comfortable cruising in offshore saltwater, yet must also maintain consistent, slow trolling speeds. Additional requirements include cabin accommodations that are comfortable, but not necessarily palatial, and lots of storage for gear, ice and fish.

The ideal size of the cockpit takes into account the size of the fighting chair and the distances required to maneuver around it, as well as sufficient space for gear. This results in a figure for the boat's overall width, or beam. Since a typical ratio of beam