Vestas Sailrocket 2’s Record Run: A Decade in the Making
If at first you don’t succeed, try and try and try again! When Australian sailor Paul Larsen launched his first Sailrocket back in August 2004 with the goal of setting a new world sailing speed record, he never expected nine full speedsailing seasons of trials, tribulations, occasional success and intense frustration would pass before a whole new boat, Vestas Sailrocket 2, finally succeeded in November 2012. All credit to Larsen and his long suffering partner, Helena Darvelid, plus designer Malcolm Barnsley for their unbeatable optimism, sticking with the project through thick and thin, despite the fact that it often seemed like a massive struggle toward ultimate failure.
The Sailrocket design concept is based on a type of proa, or single tack multihull, with its rig canted to windward like a windsurfer, so that there are no overturning heeling forces. In fact, at speed, Vestas Sailrocket 2’s tiny leeward hull flies completely clear of the water, despite the huge power required for the boat to reach its potential, with wind speeds multiplied by a factor of up to 2.5 during its record-breaking runs.
The first Sailrocket carried an overgrown windsurfer-style “soft” sail, because there wasn’t enough money or time to build a solid wingsail before Larsen and Darvelid launched it on Portland Harbor in the south of England to put it through its paces. Unfortunately, watching Sailrocket in action on the 500-meter course close to the beach in the lee of the Chesil Bank, many of the problems that Larsen would have to surmount quickly became clear as he made his first half-dozen runs in a 20-25 knot breeze. Among othe things, sitting at the back of the hull in a cloud of spray, Larsen could hardly see where he was going as he struggled to sail straight down the course, avoiding moored yachts, windsurfers and shallow water on a boat that was wider than it was long, and which soon proved to be a complete nightmare to control.
It also took much longer than expected to tick off first 20, then 30, 40 and eventually 50 knots. A solid wing rig provided a big power boost and it was hoped it would also enhance control through its greater stability. But it was so powerful Sailrocket began acting like an unguided missile, running up the beach at full bore or doing airborne loop-the-loops. Mercifully Larsen was never seriously hurt, but he surely scared himself (not to mention Darvelid) silly with increasing regularity. The Sailrocket team also abandoned the Portland speed course due to the unpredictable wind and traffic, moving its record attempts to Namibia, where Walvis Bay provided reliable strong wind across flat water with little apart from flamingos to get in the way.
Six years of effort eventually took Sailrocket past the magic 50-knot barrier, but French kitesurfer Sebastien Cattelan had already gotten there in 2008, which was a huge disappointment for Larsen. Because Sailrocket couldn’t be sailed any faster without major risk to the pilot, he finally launched a second Sailrocket in March 2011. “The [first] boat at speed was like flying an arrow backwards. It just wanted to end-for-end, either laterally or vertically,” Larsen says. “The second time it flipped over I thought, ‘Right, that’s it. It’s not worth investing any more time in this boat.’”
The new boat was funded by the Danish wind turbine manufacturer Vestas and incorporated the many hard lessons learned aboard its predecessor, enabling a more sophisticated assault on the speed record using the same design concept. Among the more obvious changes was the positioning of Larsen’s cockpit in the bow, so he could see where Vestas Sailrocket 2 was heading at the hoped-for 60-knot speeds without being blinded by spray.
Anyone expecting immediate success would have been disappointed. Vestas Sailrocket 2 ticked off 20, 30 and 40 knots easily enough, but after two long sessions at Walvis Bay the boat was stuck at around 50 knots, providing much the same top speed as her predecessor, albeit with a good deal more control. The problem lay in the cavitation and drag that developed across the huge main foil, which carries the weight of the hull. Finally, during the boat’s third, most recent session at Walvis Bay, minor tweaks to a completely new and much smaller main foil allowed Vestas Sailrocket 2 to fulfill her well-earned destiny, setting new 500 meter (65.45 knots average, marking a massive 10-knot jump ahead of the kitesurfers) and 1 mile (55.32 knots) world speed records, and hitting a top speed of over 68 knots in the process.
Which leads to the question: what next?
“That last run [of the season] took things to a new level,” Larsen says. “I had become accustomed to 60 knots. I could sense the leeward pod flying too high. I had nothing else to ease to bring it down except to slow down…If we had another opportunity in exactly the same conditions, I’m pretty confident we could have made another significant improvement on the record. That said, we need to sit down and review the safety aspects of the boat. Mistakes could be lethal now.
“The next big thing for our concept would be to make it practical, where it can cross an ocean,” Larsen adds. “We have a strong and passionate team…Sailrocket has left us wanting for more, but we need to choose our path carefully.”
As for the record, while Larsen thinks his boat could “comfortably see the other side of 70 knots,” he’s “curious to find out how others will meet the latest mark he has now set. “It’s going to be interesting to see who or what comes after this record,” he says. “Even with nearly 10 knots up our sleeve, I don’t feel [the record] is safe or that our job is done. I think it would be sad if no one came after us. We would rather leave a legacy of inspiring people than destroy their will to compete. Hopefully we have shown people with fertile minds and passion for design that everything hasn’t been done.”
Photos courtesy of Helena Darvelid/Vestas Sailrocket 2