boats are a blast. “Who wants to design a slow boat?”
Kirby likes to ask. “Or own one, for that matter.”
The wheel was a Neolithic invention. It appeared on the
scene 5,000 or so years ago, part of a suite of advancements
in agriculture. Sailboats came earlier. Australia was settled
at least 50,000 years ago, and the first humans didn’t arrive
on the continent by foot. Three thousand years ago, Odys-
seus himself was “sailing the winedark sea for ports of call
on alien shores.” Christopher Columbus crossed the Atlan-
tic, by sail, in 1492—marking the start of several hundred
eventful years of wind-powered global travel. Only in the
past 200 years have the steamship, internal- combustion
engine, and jetliner erased the sailing ship’s primacy as a
means of transportation. Sailboats themselves, however,
have held on, not as necessity but as sport.
No surprise then that in 1969, when Bruce Kirby got
a call from his friend, the Montreal-based industrial de-
signer Ian Bruce, about drafting a new sailboat, the brief
was for a piece of recreational equipment—a “car-topper”
to go along with a line of outdoor gear (tents, cots, camp-
ing chairs) for the Hudson’s Bay Company retail chain. “I
didn’t even know what a car-topper was,” Kirby recalls.
The craft had to be easy to transport and rig in order to
make it as painless as possible to get out on the water.
The dinghy wasn’t the first boat Kirby had dreamed up,
but he wasn’t designing them full time. He was working as
an editor at a sailing magazine, living (like now) on the Con-
necticut shore. As a designer, he was self-taught, nicking a
copy of Skene’s Elements of Yacht Design, originally pub-
lished in 1904, from a family friend and understanding,
he estimates, about a third of it. But Kirby had “three-
dimensional eyeballs,” as he describes it; he had no trouble
envisioning the shape of a hull. And as a world-class racer
of small boats, he knew what a fast one should feel like.
Kirby sketched on ruled paper as they talked. When they
hung up, he brought it to his 7-foot drawing board and be-
gan to tinker. He knew he had to “get the numbers right.”
His first consideration was what’s known as the prismatic
coefficient, which defines the shape of the vessel. Is it a tub
or a knife? Or, in the language of yacht design, is the hull
“full” or “fine”? A rectangular barge has a prismatic co-
efficient of 1 because its hull entirely fills the prism made
by its length, beam (or width), and draft (its depth). Most
sailboats have a coefficient between 0.5 and 0.6, mean-
ing about half that volume. If the prismatic coefficient is
too high—if the boat is too fat—it will be slow, especially in
light wind. But if the coefficient is too low—if the boat is too
skinny—it will slice through the waves rather than ride up
on top of them, or “plane.” A sailboat that planes well is fast,
but more important, it’s fun. High up out of the water, wind
and sail become more than the sum of their parts. Kirby set-
tled on 0.55, a just-right number to make a well-balanced
boat: fast but stable, neither too tippy nor too tubby.
But only if the sailor worked for it. Dinghies depend on
“live ballast,” i.e., a person leaning, or “hiking,” out over
the side. A big sail makes a boat zip, if its sailor can keep it
flat. Basic physics says that their ability to do so depends
on their weight, which of course varies from person to per-
son. So, Kirby had a second number to choose: the ratio of
sail size to the hull’s displacement, which depends on the
weight of the boat plus its human. Kirby dialed in his dinghy
to perform best with 180 pounds of flesh—in his words, “a
good-size guy working like hell to go fast.” The decision
was in part selfish; it described Kirby at the time.
Within a couple of weeks, Kirby had a sketch for Bruce.
“He was in a bit of a hurry,” Kirby says. When Hudson’s
Bay decided against selling a boat at all, Kirby told Bruce
to hold on to the design: “I put a little more oomph in the
boat than you asked for. It’s going to be a pretty hot little
boat if we ever have a chance to build it.”THE CHANCE CAME SOON ENOUGH. IN
October 1970, Kirby’s magazine planned a promotional
regatta for sailboats that cost less than $1,000, to be held
at the Playboy Club in Lake Geneva, Wisconsin. Kirby
and Bruce built a prototype of the car-topper and rigged
it for the first time the day of the race. They came in sec-
ond place. The bend of the mast didn’t match the shape of51THE MASTERPIECEHome Port
Bruce Kirby,
Olympian and
sailboat
designer, on
the shores of
Long Island
Sound.POPSCI.COM•SPRING 2019