It all started when lakers Wayne and Felicia Davis were watching off-shore power boat racing on TV. Felicia noticed that the newer tunnel hull boat designs were outrunning the more traditional “deep V’s” -- so much so that they competed in different “class” categories.
Tunnel hulls are built catamaran style -- essentially two sculpted pontoons connected by a reinforced deck. The resulting hull shape achieves minimal wetted surface when on plane and creates a cushion of air underneath the deck that helps minimize displacement and drag at high speeds. Tunnel hulls run fast and relatively fuel efficiently.
But there’s a downside: They can be prone to “taking flight” on the air cushion, losing their grip on the water and possibly flipping over. And, for the everyday boater, a tunnel-hulled “cat” has very limited internal volume where features such as bunks, galleys, heads and lockers can be located. Only the area inside the narrow pontoons provides weather-protected space for crew comforts.
Deep V’s, on the other hand, run on a single hull -- essentially a big V-shaped covered bathtub -- and below decks there’s lots of room that, in boats longer that 26 feet or so, becomes cabin space.
Wayne Davis, too, liked the way the cats ran, but preferred how the deep V’s looked. “It would be nice,” he remembers thinking, “if you could combine the two for the best of both designs.”
That thought prompted the Da-Vee hull design, awarded a U.S. patent in November of 2007.
Wayne’s innovation was to create a rectangular tunnel centered in the aft section of a traditional hull, retaining the V shape forward to cut through waves and provide usable space below the forward deck. On plane, the boat would mimic the water contact of a tunnel hull design; at displacement speeds, it would look and act like a traditional V hull. And at anchor or dock, much of a V hull’s forward cabin space would have room for creature comfort appointments.
An inherent tinkerer who works as a plant electrical technician at the Greif Corp. in Amherst, Davis, 60, began experimenting with his idea. A radio controlled model boat was his first test vessel: He cut into the hull and fabricated a tunnel running from the transom halfway forward. As best he could tell watching from shore, the resulting hybrid hull shape performed just fine, jumping up on plane, running smooth and level, and responding well to rudder inputs.
Encouraged, he found a rather neglected 15-foot Glastron GT outboard sport boat offered online. He enlisted the help of boating friend Ben Helmandollar of Hardy (the two had met back in the early 1980s; also a tinkerer, Helmandollar later experimented with a skier-controlled, jet-ski-based towing vessel). The pair hauled the boat home from Pennsylvania, flipped it over and opened up a rectangular hole about 2 feet wide by 8 feet long and added wooden framing and fiberglass to form the sides and top of the tunnel. Initial water trials of the modified hull showed potential but suggested the tunnel was too wide: the boat wouldn’t reliably stay on plane.
Helmandollar located a second 15-foot Glastron GT, which was purchased and modified using what had been learned from the first full-scale attempt. A smaller tunnel was created -- this one about 12 inches narrower -- and a gradually-deepening inverted V was sculpted into the forward section of the keel to channel air into the tunnel cavity, creating negative pressure inside the tunnel that improves stability. Run using the same 90 horsepower outboard engine as used on yet a third Glastron that Helmandollar found as a comparison boat, the modified boat is capable of 53 mph, about 3 mph faster than the unmodified version. The design also cures the “chine walking” instability that the unmodified Glastron exhibits at high speeds.
Confident their testing showed promise, the experimenters contacted Eliminator Boats, a California-based maker of performance off-shore vessels. Company President Bob Leach sounded curious and, after reviewing video of Da-Vee hull test runs, invited Davis and Helmandollar to visit his West Coast design and manufacturing facility. In the course of their discussions, Leach committed to building a 30-footer using the Da-Vee hull design and selling it at cost -- but only if Davis could find a forward-thinking customer willing to spend about $100,000 on the rig. That search is ongoing.
Davis and Helmandollar have also reached out to several East Coast builders, finding some interest from Superboat in New York, but so far no commitment to build a boat using the patented design.
“This is a labor of love,” Wayne Davis said. “It’s been interesting to explore how the design transfers from idea to a working prototype. It shows promise; we just need to find the right boat builder/customer combination to make it all happen for real.”