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from WoodenBoat November-December 1998
Maine lobsterboat + Chesapeake deadrise =
Below Decks, the Rabbit 38 offers compact cruising accommodations for a couple. The pilothouse and cockpit provide plenty of open space.
Kaufman Design, working on the upper western shore of Chesapeake Bay, has drawn the Rabbit 38 for Mast & Mallet Boatworks to build at Galesville, Maryland. This new bull does indeed look to be the child of a marriage between a Maine lobsterboat and a Chesapeake deadrise. Mike Kaufman gave the new 38 a sweeping sheerline forward. If not so strong a the curve seen on some Down East lobsterboats, it matches the profile of lower Chesapeake boats intended for working in open water. (Deadrise built north of the Potomac River tend to be flatter of sheer.) The 38's considerable flare forward seems to come from the lower Bay boats, and the tumblehome aft (while more Common to lobsterboats) can be found on both types.
The Rabbit 38's chines (inherited from the Chesapeake side of the family) enter the static waterline well aft. Kaufman explains that this allowed him to draw substantial deadrise forward"essential for a smooth ride." The deadrise (athwartships V-shape to the bottom) decreases from 30- at 25% of the waterline abaft the stem to 9 degrees the transom. This configuration, combined with a narrow waterline beam, should extend the easy motion throughout the speed range. At slow speeds, the wake will be low and the handling predictable.
Cold-molded construction produces a strong and light boat. Computer-generated, full-sized Mylar frame patterns allow builder Joe Reid to adjust the topsides to suit individual owners at reasonable cost.
Compared to the ubiquitous deep-V hulls of similar dimensions (which might carry 24' of deadrise all the way to their transoms), the Rabbit should demonstrate greater initial static stability. It likely will punch just as smoothly through a healthy chop and consume less power in the process. Up to a point, the deep-V boats will push on faster into tall waves-if our machinery and fuel budget can handle the task. Extrapolating from the measured performance of the Rabbit 34 (21 knots at 10,500 lbs with a 220-hp diesel), Kaufman predicts that the 38' hull will top out at 25 knots and cruise at 20 knots. The hull has a K(aufman) value of 32. The K-value is a predictor of hull efficiency. K-values of 30 to 33 indicate hulls that will be easily driven throughout their speed ranges. A lower value, say 27, suggests that a hull will be extremely efficient at one particular speed. A higher K-value, say 40, tells us that the boat in question will prove to be, well ... not so easily driven.
The first Rabbit 38 will be powered by a single 330-hp Cummins diesel. A twin-screw option will reduce the boat's draft by 12 "and improve lowspeed maneuverability. It also should increase original costs, cause greater hydrodynamic drag, and decrease propeller protection.
Kaufman drew the accommodations to house a couple. He included virtually all the amenities: a galley with refrigeration; a full head with shower; and a V-berth/settee, which doubles as a dining area. If an observer comments that the arrangements seem a little tight in places, the designer can point to the cockpit (which occupies nearly half of this hull's usable length). That's where most of us will choose to take our meals in anything short of a moderate gale. If a client insists, the designer will enclose more volume by extending the length of the optional pilothouse.
Joe Reid and his crew at Mast & Mallet will build the 38's hull with two fore-and-aft layers of 1/2" cedar planking over transverse fir frames. Everything in sight will be coated and/or glued with epoxy. Two layers of 10-oz fiberglass cloth will help to protect the hull from cosmetic damage. From "patterns to rollover," hull construction should consume about six weeks. Kaufman describes the results as "low-tech, highly dependable, and strong." He estimates that a comparable fiberglass production boat would weigh some 1,500 lbs more than the wood-epoxy Rabbit.
The designer plans to provide the builder with full-sized Mylar patterns for the frames of each Rabbit 38. Accordingly, nuances of hull shape above the chines (flare, tumblehome, etc.) can be altered to reflect owners' preferences. Interior layout can vary wildlyso long as the engine location remains constant.
Kaufman concludes that the computer-assisted working relation ship between designer and builder results in a "custom, built-to-order boat at the cost of a production boat." The expense of maintaining a Rabbit should prove equal to, or less than, the costs associated with similar fiberglass hulls (see WB No. 100). In addition, the Rabbit offers the feel and pleasure of wood-and isn't it a fine looking boat.
Mike O'Brien is senior editor for WoodenBoat.
Design information from Kaufman Design. Inc., 40 Boone Trail, Severna Park, MD 21146.
The deadrise hull should combine efficiency and easy motion throughout its speed range.