THE BIG FOOT HULL FORM—

The Big Foot Hull Form is based on years of experience and research. It is an exceptionally versatile hull form and we believe it is one of the best designs available to meet the needs of our times.

Big Foot Marine has developed a wide beam hull form that is ideal for a multitude of different applications. Using this form gives our vessels their "large footprint," by which we me that they are beamy, shallow draft, fuel-efficient, stable, semi-displacement and versatile. In addition, this design is cost-effective to build using any of several readily available materials, such as, steel, aluminum, plywood, flat panel glass, in addition to composite materials. As you explore this website you will see that each boat featured has this hull form in common.

The under body of the hull form is similar to that employed by the fuel conscious Washington State Ferry System and provides unparalleled 2.5 length to beam ratio. Inspiration for the hull design also comes from the Chincoteague Skiff, a 19th-century Chesapeake Bay oysterman hull, as it appears in Chapelle's "American Small Sailing Craft." This is a well-proven design that provides a comparatively beamy and shallow displacement hull form.

The Big Foot Hull Form endows our vessels with the virtues of stability, large load carrying capability, excellent sea-keeping qualities and a comparatively small wetted surface—making it easy to drive through the water. Further, the shallow displacement hull results in a relatively low rear quarter beam buttock angle (six degrees). This significantly reduces the penalty for cruising somewhat above displacement speed, for example, from 1.34 to 1.5 times the square root of the waterline length (8.5 to 9.5knots) in a vessel with a 41' waterline. This hull form moves through the water with such ease that it would make an ideal hull to push with a fuel cell electric power train in the interest of silent running. Or one might consider a hybrid diesel/electric drive.

In the interest of increased stability many of our designs combine the Big Foot Hull Form with the Big Foot Keel. This is a wide keel design that creates sufficient area to hold the bulk of a vessel's fuel, water, waste, batteries and ballast, not only below the waterline, but below the vessel's hull. Achieving a large amount of stowage space while only marginally increasing the vessel's wetted surface and resistance. It also permits a vessel to be beached in an upright and stable position if desired.

 

 

PUTTING IT TO THE TEST—

The Big Foot Hull Form concept has been extensively tested in real world conditions. Rather than tank testing a small balsa wood model, Big Foot Marine built a small "proof of concept"vessel. The 25 foot Shadowfax—a 4,500 pound, 10 foot beam vessel. She achieves hull speed with her 10 horse-power Yamaha four-stroke engine and has demonstrated extraordinary sea-keeping abilities throughout the waters of the Pacific Northwest. She has successfully voyaged as far as Glacier Bay, Alaska. Shadowfax has also vividly demonstrated the close quarters handling capability of the lightweight hull.

We are frequently asked if greater speeds can be achieved using an engine with more horsepower. Only marginally so, there will be a greater impact on the vessel's power than on speed. If you have need for a fast boat the recommendation is to put a small, fast boat on the stern. This boat could be launched on a moment's notice and easily accessed from the stern swim step. Off you go—the larger vessel left at anchor, ideal for station keeping. Keep in mind that faster boats are more vulnerable in rough weather. A stable hull form may get you home a bit slower, but you can count on it to get you there even if you can't count on the seas to remain calm.