Skip to main content

America's Cup 33

Ian Campbell of the University of Southampton’s (UK) venerable Wolfson Test Unit takes data provided to him by SAIL and runs it through their velocity prediction programs and the WinDesign VPP developed in conjunction with Clay Oliver’s Yacht Research International. His detailed analysis, which begins on page 14 of SAIL’s February issue, suggests that BMW Oracle’s trimaran, USA, can fly a hull in just 8 knots of true windspeed, can sail to windward at twice the true wind speed (TWS) and can reach VMG speeds about 50 percent higher than true wind speed.

Campbell uses estimated weights and sail areas for both boats and also scales a C-Class catamaran, another class with no weight restrictions, up to 90ft. The estimated data for Alinghi’s catamaran, A5, and BMW Oracle’s USA, compare favourably with the scaled up C-Class cat.

Because these boats are so fast, apparent wind speed and wind angle will hardly change when these boats bear away on a downwind course. That means, says Campbell, that achieving maximum speed is really going to depend on how well each team knows their boat’s optimum sailing angle for any given wind strength. Both crews will try to foot fast rather than point higher and go slower.

Downwind, Vmg speeds with a Code 0 headsail can produce apparent wind angles of just 22–28 degrees. But because of more sail area and the ability to carry water ballast effectively, USA could be 20 seconds/mile faster than A5 in 8 knots of wind. In fact anytime the boats are flying a hull, says Campbell, the data shows that USA is the faster boat.

Because USA’s wing mast can quickly produce camber coming out of a tack, that will help it to fly a hull more quickly. And even though large Code 0 headsails on A5 could reduce slightly the speed advantage downwind, any time the boats are flying a hull USA should be faster. Of course with large and staggeringly powerful boats like these, anything might happen. But if the engineers and builders have done their job, and the USA crew can avoid breakdowns, they should prevail over A5, in the 33rd America’s Cup Match, and possibly by a considerable margin.

For an in-depth analysis of both boats, including polar diagrams and estimated speed differences over a full range of windspeeds go to page 14 of SAIL’s February issue.



A Force for Change: Captain Liz Gillooly

I first heard about Capt. Liz Gillooly in 2016 from my cousin while working three jobs in our shared hometown on the North Fork of Long Island and living with my parents to save money for a boat. But despite being the same age and growing up only 13 miles apart, Liz and I never more


Sailing in the Growth Zone

The Goal This year, I’ve had a specific goal to be a better sailor. Some people have laughed and said, “Why do you need to be a better sailor? This was my 22nd year racing on the same boat, with the same crew. I like to win and want to make sure we stay at the top of the fleet. more


The Extraordinary Life and Mysterious Disappearance of Thomas Thor Tangvald

The first boat Thomas Tangvald ever owned was just 22 feet long. She was an odd craft, a narrow plywood scow with a flat bottom, leeboards on either side, and square ends—little more than a daysailer with a rotting deck and tiny cabinhouse tacked on. Thomas paid just $200 for more


USVI Charter Yacht Show Showcases a Flourishing Industry

As the U.S. Virgin Islands continues to attract sailors seeking to charter and explore the pristine territory on their own, the immense growth and expanded options for a crewed yacht or term charters have exploded here over the past five years. Last week, the USVI Charter more


Personal Locator Beacon Wins Top Design Award

The Ocean Signal RescueME PLB3 AIS Personal Locator took top honors at the 2022 DAME Design Awards, while Aceleron Essential, a cobalt-free lithium-iron phosphate battery with replaceable and upgradeable parts, won the first DAME Environmental Design Award. Announced each year more


EPIRB in the Golden Globe Race

Tapio Lehtinen’s boat sank early this morning southeast of South Africa while racing the Golden Globe Race, a faithfully low-tech reproduction of the 1968 Sunday Times Golden Globe. The boat went down quickly and stern-first according to the skipper’s emergency transmissions. more


Victory, Tragedy in the Route du Rhum

The 2022 Route du Rhum was a highly anticipated event in the ocean racing calendar, but few could have predicted exactly how challenging, dramatic, and tragic it would ultimately prove. French yachtsman Charles Caudrelier took home gold aboard the Ultim maxi trimaran Maxi Edmond more


Boat Review: Lyman-Morse LM46

Lyman-Morse has been building fine yachts in Thomaston, Maine, ever since Cabot Lyman first joined forces with Roger Morse back in 1978. With experience creating and modifying boats built of various materials, backed by its own in-house fabrication facility, the firm has more