Engine design and packaging are key
to bringing surfer's dream to life
By John Lewis, Northeast Technical
West-coast inventor Bob Montgomery first learned the
way of the waves in the 1960s riding Southern California
beachbreaks as a teenaged protιgι of surfing
legend Duke Kahanamoku. Like many other surfers, Montgomery
imagined a dream machine-a one-man hydrokinetic rocketship
that would combine the freedom of surfing with a water
ski's ease-of-use and maneuverability. "I wanted to
ride a high-performance, motorized surfboard," recalls
the 50-year-old ex-pro surfer.
See the Powerski in action! Click here.
Now, due to his own determination and the availability
of the latest materials and CAD tools, he is about to
see his dream come true. It has taken the form of the
Igniter 2000? model Powerski? Jetboard?,
a new product from Powerski International, Inc. (PSI),
a company he founded in the garage of his San Clemente,
CA home. Montgomery is currently building a hundred
prototypes for testing this summer, and production models
should go on sale later this year.
He says he has three U.S. and 27 foreign patents, with
61 more pending worldwide, for this water craft that
allows the rider to stand rather than sit, as is the
case with most competitive products- and it's making
quite a splash in the popular press. For example, the
Igniter 2000 and its proprietary engine won the Popular
Mechanics Design and Engineering Award for the new
Millennium. It's also been featured in magazines such
as Popular Science, Watercraft World,
and Boating World. Among the Igniter 2000's engineering
A proprietary two-stroke, water-cooled engine that
puts out between 30 and 50 hp, depending on displacement.
The 6.5-inch thick, 50-cc engine weighs about 40 lbs,
but use of a metal matrix composite material should
drop the weight to about 28 lbs, Montgomery says.
An axial-flow jet pump that delivers 350 lbs of
thrust through a proprietary gear-reduction transmission.
The gear reduction, built into the bottom end of the
engine, is new to the power watercraft industry. It
enables engineers to match the engine's optimum rpm
to that of the jet pump to enhance the craft's performance.
A design that puts the center of gravity under the
rider's feet, rather than behind or in front of the
rider as is the case with similar sports water craft.
Dual "hydrosteps" on the bottom of the hull that
put the pivot point directly under the rider's feet,
enabling high-speed planing and turning. They lift
the craft partly out of the water as it skims along,
and direct the line of water rushing past the rails
during top-speed turns, stabilizing the craft.
A four-ft-long "armpole" consisting of steel cable
and a sleeved wire harness covered by injection-molded
rubber. The rider holds the grip on the end of the
armpole that has start and stop buttons, left and
right thumb throttles, speedometer and fuel gauges,
and a safety kill switch.
Design of the Igniter 2000, which has been a ten-year
project, required overcoming several engineering challenges.
Dealing with five significant natural forces: weight,
buoyancy, hydrodynamic lift and drag, and thrust, Montgomery
combined a high thrust-to-weight ratio with a hull/rail
design and center of gravity placement that stabilizes
the craft at all speeds. The design also enables high-speed
planing and high-thrust G-force turns with simple shifts
in weight of a rear-mounted rider.
But the real key was packaging the jet drive system
inside the hull under the rider's feet. AutoCAD, from
Autodesk (San Raphael, CA) and Pro/ENGINEER from Parametric
Technology Corp. (Waltham, MA) were critical tools in
the design process.
Sitdown & heavy. As a pioneer in the industry,
Montgomery saw changes in the personal watercraft (PWC)
design. As a standup watercraft, he says, the typical
Jet Ski had proved relatively unstable-riders found
it difficult to maintain a standing position because
of the craft's forward center of gravity. Kawasaki's
solution to the problem was to go from "standup" to
"sitdown." The Jet Ski became a heavy, sitdown, square-railed
directional jet-drive watercraft. The move by Kawasaki
and other major industry manufacturers toward a heavy
sitdown craft built up Montgomery's confidence in his
plan for a much more hydrodynamic, standup watercraft.
Where they went sitdown, he would go standup. Where
they went heavy, he would go light.
"They lost the `personal' from the personal water craft
when they went sitdown," he asserts. "The new machines
were heavy, bulky, almost boats." So, Montgomery left
the Jet Ski industry and set out to help pioneer the
The first actual jetboard/motorized surfboard appeared
in the 1960s. The "Bloomingdale Jetboard," a handle-less
standup craft designed by Renard Storey, featured a
low-powered (3-5 hp), 10-lb, 80cc engine capable of
moving the craft at a speed of no more than 3-5 mph.
Storey had designed his jetboard for surfers so they
could eliminate paddling, according to Montgomery, who
had heard about the original jetboard for years before
finally getting a look at one in the early 1980s. When
finally he saw the Bloomingdale board, he says, he knew
why surfers hadn't taken to the low-powered craft.
"It was built with a `putt-putt' mentality," he recalls.
"No thrust, so no turns." For Montgomery, the limitations
of the Bloomingdale board only confirmed for him the
efficacy of his own design, which had taken shape years
before he finally saw Storey's design. In the years
before ever assembling material for building his first
jetboard prototype, he mentally "pre-engineered" his
version of the standup PWC: a high-performance "power
ski" board long, narrow, buoyant, lightweight, low-profile,
and waterproof-propelled by a compact, powerful, jet
Montgomery continued to refine his ideas, and in 1981,
he joined Surf-Jet Corp., Janesville, WI, the one manufacturer
that shared his belief in the standup PWC. As new product
manager for the company's power-operated standup craft,
he designed the production hulls for the Surf-Jet Models
236 and 275, earning a place on the patent records for
his efforts. Then, as the company's west coast marketing
and sales manager, he began marketing the Surf-Jets.
His extensive knowledge of design, engineering and manufacturing
helped make the Surf-Jet a force in the PWC market in
But the Surf-Jet, as Montgomery saw while with the
company, left plenty of room for the sort of hydrodynamic
PWC he was designing and building. The position of the
Surf-Jet's large engine-deadweight on the tail-placed
the craft's center of gravity behind the rider, which
cut down maneuverability. The standup Jet Ski's instability
problems had stemmed from the placement of the craft's
center of gravity in front of the rider.
Montgomery offered Surf-Jet his ideas for what would
eventually become the Powerski Jetboard-with the center
of gravity beneath the rider's feet, the rider's weight
would dominate the craft to provide complete steering
control. But, he says, Surf-Jet wasn't interested, and
Montgomery moved on. In 1987, the entrepreneur in Montgomery
set out to meet the challenge of pulling off a major
marketing success without the benefit of initially having
any money to pay for it. He started in his garage, hand-crafting
his dream machine.
In 1990, to formally raise the funds necessary for
taking the craft to the working prototype, pre-production
stage, he formed the HydroForce Group General Partnership.
During the next few years that the jetboard took shape,
Montgomery struggled to keep focused on his mission,
even working other jobs to pay the bills as he labored
in his off hours. All the while he operated a "stealth"
research and development campaign, strategically keeping
the prototype hidden from the public (and competitors)
as he slowly secured patents, trademarks and other intellectual
property rights protections.
His work was not without conflicts, however. On one
occasion he had to resort to fisticuffs to thwart a
group of would-be thieves intent on stealing his design.
Once the Powerski Jetboard was fully protected, Montgomery
revealed his prototype to the world, securing product
placement stories for the craft in national magazines.
A card-carrying member of the Screen Actors Guild, he
has also acted in and performed stunts for numerous
TV productions and in two Hollywood motion pictures,
including Kevin Costner's 1994 flick Waterworld.
In 1995, Montgomery co-founded PSI and moved to production
facilities in Brea, CA, where he finished design of
the Igniter 2000.
Designing the dream. The most significant challenge
facing Montgomery in bringing his jetboard idea into
reality was the engine. "I needed an engine with the
horsepower-to-weight ratio that would give the consumer
the ultimate jetboarding experience," he says. After
an extensive worldwide search failed to turn up a suitable
prototype, he says, he decided to build his own. Hiring
Bjorn Elvin as PSI's engine project manager, Montgomery
put Elvin's small-engine experience-gained while working
at Husqvarna's motorcycle and chainsaw divisio