What it’s Like Full-foiling Aboard an America’s Cup Boat

Author:
Updated:
Original:
sailing on a knife edge

Controlling an ACC catamaran means keeping your cool while sailing on a knife edge

Bermuda’s 75-degree water makes sailing foiling catamarans pretty fantastic. Let’s be frank, San Francisco is a cold place to sail. And the fact that you’re on a boat being hosed with spray and 50 knots of apparent wind as normal operating conditions doesn’t make things any easier. Dry suits were common, wetsuits were a must. While advances in control systems and foil design have made the modern 50ft America’s Cup Class catamarans capable of sailing “dry” laps, the unavoidable splash still makes for a generally wet ride for the six-man crews. That said, for the four grinders on board, as soon as we start our day we’re warmed up, and a good bit of spray is a welcome relief from the balmy Bermuda southwesterlies.

Once we’re off the dock and have gone jib-up, we slowly make our way through Dundonald Channel onto Bermuda’s Great Sound. “Slowly” means closehauled and flying a hull at about 13 knots. As soon as we’re clear of the reef and happy with our systems checks, it’s as simple as putting the bow down and building to takeoff speed. In 12 knots of wind, this is not much of a press, although loads do increase as the boat strains, dragging both rudders, their elevators and the L-shaped leeward daggerboard through the water, along with 50ft of leeward hull.

11-sidebar-1-racing-an-acc-campbell-author-head-shot

By now the grinders will have already started pumping pressure behind the hydraulic lines to prep for the upcoming maneuvers and trim adjustments. So as soon as takeoff speed is achieved our helmsman, Jimmy Spithill, simply makes a quick pitch adjustment to the leeward daggerboard, activating a set of hydraulic cylinders to push the head of the daggerboard aft, thereby changing the angle of attack of the horizontal portion of the foil. Once the angle is high enough and the lift it creates exceeds the weight of the boat, there is a short jolt as the leeward hull breaks the surface of the water and the boat releases into full-foiling mode.

As it does so, a quiet comes over the boat, and there is no longer any spray washing over the leeward bow as the boatspeed quickly doubles. While it’s true the effort the sailors are putting into the pedestals combined with the communications and 50 knots of apparent wind make for a noisy environment overall. The boat’s actual movement is quite dampened because we’re now riding above the sea state. Gone is the pitching, slamming and hacking into the chop of traditional sailing.

The course for AC35 is a short one: following a reaching leg there is a downwind leg, an upwind leg, another downwind leg and beat, then a short reach to the finish off the Cup Village; total time, around 20 minutes

The course for AC35 is a short one: following a reaching leg there is a downwind leg, an upwind leg, another downwind leg and beat, then a short reach to the finish off the Cup Village; total time, around 20 minutes

That said, there is little margin of error. The entire time the boat is airborne, Jimmy’s steering, the angle of attack of the foil, and the angle of the wingsail and its twist all contribute to keeping the boat aloft. These elements, in turn, are all controlled using hydraulic pressure created by the wattage put into the grinding pedestals. As a practical matter, every adjustment creates energy demand, and conservation is paramount to having enough energy in the tank for maneuvering over the entire racecourse. At the same time, any misstep in helm, foil or wing trim can send the boat careening back down into the water. Thirty knots back to 10 knots makes for some significant g-force, and the urgency of getting the boat back on the rails is obvious. In the end trying to keep calm and continue to do your job at 90 percent, maximum heart rate is one of the biggest challenges of sailing an ACC cat.

For more on what it’s like sailing and racing a full-foiling ACC catamaran, including video and insights into AC35 strategy and tactics, visitsailmagazine.com/racing/americas-cup

Related

TOTW_PromoSite

SAIL's Tip of the Week

Presented by Vetus-Maxwell. Got a tip? Send it to sailmail@sailmagazine.com The back door Satisfied with your headsails? So was I, until one day I took a long, hard look up the luff of my genoa, making sure I inspected the leeward side as well. The sail had plenty of life ...read more

02-Lydia12-01

Losing Sight of Shore

I arrived on the docks of Beaufort, North Carolina, in late April with two backpacks filled with new gear—everything I’d need for my first offshore passage. Though I’d been sailing for 16 years, graduating from dinghies to keelboats to a J/122, I’d spent my time racing and, in ...read more

Squall

The Face of a Squall

They are the worst of times, they are the best of times There’s a fabulous line from an old Paul Simon song that I often sing to myself while sailing: I can gather all the news I need from the weather report. It is part of the magic of sailing, this ancient process by which we ...read more

ntcktshtrstk

Cruising Southern New England Waters

One of the most wonderful childhood vacations I can remember was back in 1971 when my best friend invited me to his family’s summer home on Nantucket Island. For a 10-year-old kid, this was a thrilling trip for many reasons, not the least of which was the fact it was also my ...read more

IMG_8287GR16Mykonos

Cultural Charters: Mykonos

In last month’s column, I covered the amazing mix of cultures that have called the Dalmatian Coast home over the centuries. Croatia cruising is like a smorgasbord of intertwined centuries, and the islands are a movie set. A little farther south, though, you’ve also got Greece, ...read more

cookinglead

Cruising: No Oven? No Worries

Many cruising boats, especially smaller ones, don’t have a conventional oven. But that doesn’t mean that you can’t have all the baked foods you want, from bread to brownies to breakfast rolls to casseroles and even a roast chicken. All it takes is the right bit of gear and a ...read more

ZK-Seaboot-900

Gear: Zhik’s Seaboot 900

A Better Sea Boot Following up on its successful ZK Seaboot 800, Zhik’s Seaboot 900 was created in partnership with team AkzoNobel and Dongfeng Race Team, the latter the overall winner of the 2017-18 Volvo Ocean Race. Designed for serious, long-distance offshore racers and ...read more

01-LEAD-FP-Astrea-42-Gilles-martin-rajet---Navigation

Switching to Solar Offshore

No sensible bluewater sailor would consider setting off on a long cruise these days without some means of generating power other than by burning fossil fuels. The good news is that solar energy is becoming less expensive by the day, making it an obvious answer for providing the ...read more