Updated November 30, 2019 15:17:12

When Brett Burvill won two races at the moth class sailing world championships in Perth almost 20 years ago, he could not have known how a small change he made to his boat would reverberate around the world.

“He finished 10th [overall], which is pretty good for a crazy new development, but he won at least two of the races I think,” recalled friend and fellow boat builder John Ilett.

“They were really spectacular, because he would not go very well at the first part of the race, and then the next part he would pass 20 boats, and then another 20 boats.

“He was just twice the speed.”

Next week, more than 100 competitors will return to the Mounts Bay Sailing Club for the 2019 World Championships, two decades after Burvill unveiled his revolutionary innovation.

He had attached a hydrofoil to his boat, which provided lift, reduced drag and dramatically increased his speed.

It also set in motion innovations which made their way to the biggest race in global yachting.

Superfast hydrofoil caused a stir

Burvill wasn’t the first person to put hydrofoils on a boat, but he was the first to successfully race them.

“There were ones done in the 1970s, with moths, and ones in the 1990s, but these were never sort of proven in racing,” said Ilett, who was an early adopter of hydrofoils.

“People experimented with it but until you actually sail around a course and win a race or win a regatta, then that’s when the concepts are proven and adopted.

“I think it was just the inspiration of other crazy boats flying around, because it had been done to other craft but it had not been done in the moth class.

“The moth class is open to any new development, so if you can make them go faster, then we gave it a try.”

The attachment of foils to the moth boats brought plenty of resistance, with some competitors concerned the increased speed and difficulty of control would kill the class.

“There was a lot of backlash to it in the beginning,” Ilett said.

“The class wanted to ban it, some people wanting to ban it, people walking away from the class and saying I’m never coming back, so there was a lot of fuss about it.”

So how do hydrofoils actually work?

Hydrofoils are not a new invention, with their use first recorded 150 years ago when a British patent was granted to Frenchman Emmanuel Denis Farcot.

He claimed that adapting to the sides and bottom of a vessel a series of inclined planes or wedge-formed pieces would have the affect of lifting it in the water and reducing the drag as it went forward.

Inventor Alexander Graham Bell, who is best known for the telephone, also built a foiled boat called a HD-4, which set a marine speed record of 114 kilometres per hour in 1919.

Since then, the technology has been used in military and passenger capabilities, but there prevalence has declined over time, with the foils susceptible to impact and also posing a risk to marine life.

Hydrofoils work in essentially the same way as aeroplane wings.

As the boat moves forward, the hydrofoil travels through the water, but the water that travels over the top does so at a faster speed.

The faster the water travels, the lower the pressure, resulting in an area of low pressure above the foil and high pressure below the foil.

The difference in pressure creates lift, allowing the boat to rise out of the water.

With the hull of the boat out of the water, drag is reduced, and vessels can reach higher speeds.

Making it to the America’s Cup

The successful application of hydrofoils in the moth class demonstrated their value to racing and saw them adopted across numerous sailing classes.

But it was their use in arguably the world’s most prestigious race that completed their emergence in mainstream racing.

“It’s pretty cool,” Ilett reflected.

“I think it probably seemed inevitable. I think I’m right that in the early days of the America’s Cup they did try to stop the hydrofoil developments, but like the America’s Cup do, they found a way around it.”

Those changes were implemented in 2013, when America’s Team Oracle completed a remarkable 1-8 comeback to claim the event 9-8 over Team New Zealand, with the yachts reaching speeds of about 80kph.

The adoption of the hydrofoil in the Cup has a benefit for those who still race the moths, with successful skippers often hired to compete in the big race.

“It’s put a lot of America’s Cup sailors into the moths class because it’s easier to get the guys out on one of of these more often — for training, for learning and getting a feel for flying,” Ilett said.

“Even the guys on the America’s Cup boats that don’t do particular jobs, they all sail on these boats too.”

Topics: sport, sailing, perth-6000, wa

First posted November 30, 2019 09:18:00