MBULI - A PROA BEACH CRUISER REVIEW designed by John Harris, commentary by Mike O'Brien
Now for something a little different. When young John Harris took over Chesapeake Light Craft (a large manufacturer of kayak kits), the drawing and building of this beach-cruising proa provided welcome diversion from the pressure of being CEO for CLC. He devoted some 400 evening and weekend hours to creating the boat. Harris named his proa MBULI, which he tells us means "folly" in Swahili, because it appeared strange to some eyes and he "wasn't entirely sure how it would come out."
Proas are reversible boats. Their "now bows" become their "then bows"?-and they can sail off in either direction at 20 knots. Unlike nearly all other boats, they are symmetrical longitudinally, rather than laterally. More than a thousand years ago, proas spread populations throughout Pacific Oceania. During the latter half of the 20th century the challenging simplicity of the type appealed to imaginative designers such as Dick Newick and Russell Brown (see WB No. 83) who created cruising proas that ranged fast and far.
To the slender double-ended sharpie hull, the designer added a mid-height chine to gain some volume and to create a "nice shadow line." The resulting interior space measures 8' in length and offers sitting headroom. Large Lexan windows help to ward off claustrophobia. A lee pod (WB No. 83, page 61) would add room to the cabin and provide buoyancy if the proa should get knocked down, but Harris couldn't work a pod's weight into his displacement equation. As built, the proa (rigged and ready to sail) weighs only 450 lbs, which allows for about 400 lbs of payload.
The builder in John Harris wanted to employ Newick-style gull-winged akas (cross beams), but project director Harris ordered plain and straight 4" aluminum tubes. MBULI got to the water faster. The tubes fit into sealed fiberglass tubes in the vaka and are lashed to the ama (small hull) with nylon line.
The dagger-rudders were patterned after those first developed by Newick. When the proa is under sail, Harris raises the forward board, which locks its rudder in place. The after board remains fully lowered, which frees its rudder.
An early sail plan for MBULI shows a schooner rig with two "bird's mouth" hollow wooden masts (WB No. 149) that carry jib-headed sails of 96 sq ft each. In a fit of whimsy, Harris outfitted his prototype with wing masts that can support a total of 224 sq ft of sail. He built the masts from birch aircraft plywood, cedar strips, and carbon fiber. When stepped in the boat the 28' sticks can rotate freely through 360 degrees (there is no standing rigging). Guided by lazy jacks, the Kevlar-Mylar-carbon fiber sails flake down into V-shaped plywood booms. Nifty.
For its first sail, MBULI found 8-knot winds on the Chesapeake. Harris reports that the boat sliced along silently at a measured 7 knots. With the ama's daggerboard fully lowered, helm balance proved near-perfect and required only two fingers on the tillers. Shunting (a proa's version of tacking) proved easy; the boat came quietly to a stop and waited patiently for the crew to sheet sails and shift rudders.
Later, Harris trailered his proa to Tampa Bay and sailed in 35-knot winds. He recalls, "I didn't have the nerve to raise sail!" MBULI reached off at speeds up to 10 knots under only the bare wing masts. All said, the wing masts have proven an uncertain blessing: "They do remarkable things for speed, and the boat points extraordinarily high. They also float, which makes recovery from capsize easier. But, in practice, they're difficult to feather quickly, and [in high winds] there is a constant sensation of being overpowered. They make the boat difficult to handle on the beach. You need to stake it down like a light airplane, lest the whole thing blow away. Stepping the wing masts singlehanded is virtually impossible."
As is a prototype's purpose, MBULI revealed another problem?the 12' ama lacked sufficient buoyancy: "On paper it will float two adults, but under sail it pokes through waves rather than riding over them. Keeping the ama right at the water's surface requires the crew to scrurry up and down the trampoline like squirrels. This technique might work with less sail, but our giant rig causes the crew to cower, white-knuckled, out at the ama. With every lull, the flying ama crashes down in a massive cloud of spray." Revised plans will show a more buoyant 16' ama.
MBULI has the makings of a fast and challenging beach cruiser. The designer-builder admits to liking the boat's shape and personality. So do I.