The Need for Speed

Horonuku sets sail-powered land speed record of 224 kmh/138.2 mph. Courtesy of Team Emirates New Zealand

Last week, on the hot dry sands of Australia’s remote Lake Gairdner, something incredible happened. On a 46.2-foot-long, 4-wheeled, carbon-fiber land-yacht called Horonuku, Glenn Ashby and Team New Zealand set a breathtaking speed record of 222.4 kmh (or 138.2 mph) in a wind-powered vehicle.

Heidi Ulrich breaking women’s windsurfing speed record of 47.16 knots. Photo credit: Jaco Wolmarans and Nils Bach

And just a few weeks earlier in Luderitz, Namibia, a windsurfer named Heidi Ulrich completed a 500-meter run at 47.16 knots setting a new women’s windsurfing speed world record. That’s pretty fast especially when considering she was navigating a channel only 500 meters long and just 14 meters wide.

These feats of speed are part of a rapidly evolving era of record-breaking sailing pursuits.  Like what Jeff Bezos, Elon Musk, and Richard Branson have brought to the modern-day space race, recent players and innovators in maritime design have also set a course to revolutionize and rethink the limits of sail-powered design.

The Starting Line

Speed records in sailing are a relatively new concept. While the first land speed record in a car was set in 1898 (at a whopping 39.24 mph), it wasn’t until 1972 that the first official sailing speed record was established.

In 1980, Crossbow II set the new world record at 36 knots

There are a couple of reasons for this.  For starters, maritime records have historically focused on commercially relevant objectives, like crossing oceans or measuring the time between two points. Point-to-point speed of sailing vessels in the 19^th century was a BIG deal—transatlantic packet ships, clippers from New York to San Francisco, and tea clippers to India and China—set important records that drove significant business to the vessel owners. As such, early records were measured in terms of days or weeks, not peak velocity.

Secondly, it’s hard to get accurate measurements while on water, and the technology needed a little time to catch up.

But even with a slow start, the quest to achieve the fastest sailing speed has become a piping hot pursuit that is pushing the boundaries of design, engineering, computer modeling, and technology.  And there is no category more exciting right now than the 500 Meter or “Outright” — the quest for the fastest recorded speed.

The Outright

 The Outright Record is a 500-meter speed test that is notable for the cutting-edge (and sometimes strange) designs which have one-upped each other for the past five decades. And in a category predicated upon free-thinking, boundary-pushing, and innovation, there remains some question as to whether what is being designed and introduced technically qualifies as sailing at all.

The first Outright Record was set in 1972 by Time Colman on a 56-ft, cold-molded plywood proa called Crossbow.  The vessel set a speed record of 26.3 knots.  Not bad for a fairly traditional sailboat design.  Over the next eight years, Colman chipped away at his own record and the design eventually developed into a unique catamaran called Crossbow II, which set four individual records.

Things changed in 1986 when a french windsurfer named Pascal Maka hit 38.9 knots in Sotavento, Spain. The era of the little and the lithe began. Windsurfing dominated the records for nearly two decades with little exception. Windsurfing records stacked one on another as sails got bigger, boards got smaller, and the globe we scoured for perfect locations: bountiful with consistent wind and minuscule waves.

In 2008, a new paradigm emerged: the kiteboard.  Kitesurfer Robert Douglas set a record of 49.8 knots besting the windsurfing record and further challenging whether larger vessels still had a place in the Outright category.

l’Hydroptère set a record of 51.4 knots and challenged perceptions about design philosophy. Photo credit: Céline Lévy

But in 2009 the 60 ft trimaran l’Hydroptère set a record of 51.4 knots and challenged perceptions about design philosophy. The French experimental sailing hydrofoil trimaran was born of the imagination of notorious yachtsman Éric Tabarly. Its multihull hydrofoil design allowed the sail-powered vessel to reach high speeds on water. Despite the radical shift in design character, l’Hydroptère remained subject to the limitation caused by cavitation on its foils.

For the next four years, the speed record would bounce back and forth between Tabarly’s l’Hydroptère and various kite surfers. The record seemed stubbornly stuck below the 56 knot ceiling. That all changed with the introduction of Vestas Sky Rocket 2.

 Breaking the Cavitation Barrier

Vestas Sailrocket 2 catapulted sailing into its very own jet age. In November 2012, the boat hit a top speed of 59.23 knots, two weeks later she broke 65.5 knots – 10 knots faster than the existing record.  A quantum leap in sailboat speed racing and design.

Vestas Sailrocket II set speed rocord of 65.45 knots and started a space age for sailboat design © Vestas Sailrocket

To go really fast under sail you need a more stable system to convert any extra thrust from gusts directly into extra speed. Once a traditional sailboat (monohull with a keel) has reached top speed (perhaps 10 -12 knots at the right wind angle), any further wind increases are wasted.  More wind causes further heeling, pushing the boat over and dumping the extra wind power. Vestas Sailrocket 2 solved that problem.

Its layout is designed to line up the force of the sail with the force of the foil resisting it in the water. This means that all the lift from the sail goes into speed, rather than trying to tip the boat over.

Sailrocket also takes a revolutionary approach to the issue of cavitation. Cavitation is a phenomenon in which the static pressure of a liquid reduces to below the liquid’s vapor pressure, leading to the formation of small vapor-filled cavities in the liquid. Simply put, under certain speed conditions, bubbles form around objects that move in water. When pressure changes and these bubbles collapse, they produce a shock wave that can damage surfaces exposed to it, such as ships’ propellers.  Cavitation becomes prevalent around 50 kts resulting in a speed barrier that marine architects compare to breaking the sound barrier in aeronautics.

The wedge foil on Sailrocket was designed to finally address this.  Unlike most foils which are shaped like a teardrop, Sailrocket’s foil is designed like a wedge and pulled behind like a plough.  The flat backside of the foil allows air to be sucked down from the surface, which creates an air pocket behind the foil. This air pocket stabilizes the cavitation and dramatically reduces drag above 50 knots.

Because of these innovations, Sailrocket has held the crown of the fastest sailboat for over a decade. A true testament to the ingenuity and strength of its design.  But that title is being challenged.

 Challenging the Crown: Syroco vs SP80

After 13 years on top, two rival teams, one in France and one in Switzerland, are now striving relentlessly to take the throne and break the 80-knot mark.

French-based Syroco (named after a warm wind originating in Saharan desert), has designed a nearly frictionless capsule-like craft with a kite sail and counterbalancing T-foil to keep it water-bound. It’s essentially a six-meter-long fish-shaped capsule pulled by a kite.

The vessel appears to be more aircraft than sailboat short of a retractable arm attached to a submerged foil, which provides steering and stability and is the only point of contact with the water.  Inside the capsule are two people tasked with maneuvering both the foil and the kite for optimal movement and balance.

The second contender is the Swiss-based SP80 Team.  Composed of a group of École Polytechnique Fédérale de Lausanne University students and engineers, the team boasts some impressive credentials, including various members of the record-setting 2009 l’Hydroptère team.

The design of SP80 is built around a trimaran shape with the main capsule reminiscent of a fighter jet’s fuselage.  Unlike Syroco, SP80 skims along the water floating on bracketed lateral foils protruding from each side.

 Why This Matters

While ego is always a large part of any record-breaking pursuit, there is more to these conquests than mere bragging rights.

Engineers from both teams hope to glean new insights around hydrodynamics, materials, and modeling, which can extend into a multitude of cross-over applications.

In particular, the team working on SP80 have focused much of their research around the study of cavitation and hope to produce a bubble-like effect that envelops underwater objects, reducing friction. Basically, turning cavitation from encumbrance to asset. This so-called supercavitation has numerous technological applications and spin-offs ranging from advanced torpedoes and propellers to improving the fuel economy and movement of large commercial ships.

As boat designers and romantics ourselves, we also like the simple aspiration of chasing dreams –sometimes just to satisfy our own curiosity and need to test the boundaries of the possible.   The journey can be as important as the destination, and what is learned along the way can have a resounding impact.

The Outright Sailing Speed Record Book