America's Cup: American Magic release video of Test Boat nosedive

American Magic's The Mule sailing in regular low-flight mode off Newport, RI © Amory Ross

New York Yacht Club's America's Cup team, American Magic have released a video of their test boat doing a spectacular nosedive while sailing off the team's base in Newport.

The team is now in Pensacola, Florida their training base during the northern hemisphere winter.

They have taken their AC75 Defiant to Pensacola.

The video is shot from one of the team's drones flying above and astern, whether the nosedive was intentional (to get test/simulator data) or accidental is not clear.

While splashdowns (where the bow enters the water with a spectacular splash) are commonplace on the larger AC75's, only one boat (and maybe two) have capsized, most of the foiling mishaps have occurred on the test boats. American Magic's test boat, named "The Mule" is designed (apart from the 38ft production M38 hull) to be as close to an AC75 as possible.

The reason for this nosedive is two-fold. First, the boat is flying very high on her foils, and second, the rudder wing breaks free of the water about midway through the low-resolution clip, and at that point the nosedive becomes inevitable. The "phenomenon" is common to all boats that have similar foiling physics such as the AC50, F50, AC72 and AC75. In the AC50 it was reckoned that a rudder wing contributed 500kg of downforce when immersed in the water, and if it breaks clear of the water then that 500kg of downforce is suddenly released triggering the nosedive.

It is not known if The Mule was flying under manual or automatic flight height control at the time.

Within the leadup to the nosedive The Mule is flying high and level, rather than going through a rear up, followed by a crash/splash which is the common routine on an AC75.

At the end of the video an on-board sequence shows the top of the rudder post being moved fore and aft - this controls the angle of attack of the wing rudder - and it is this movement coupled with the high flight height that triggered the incident causing The Mule to trip over her foils, nosedive and then capsize.

Related Articles

Explore The Remarkable Cure 55
Join Cure Marine co-founder Dave Biggar for an exclusive walkthrough Since her launch, the Cure 55 has been turning heads and earning widespread praise. Sailors have been impressed by her balanced feel, sharp responsiveness, and exhilarating performance - reaching over 21 knots SOG in just 17 knots of breeze. Posted on 3 May Hyde Sails Job Vacancies
Yacht Sales Representative and Sales & Marketing Assistant required Hyde Sails are pleased to be hiring for two positions based in our Hamble Sales Office. Established in 1964, Hyde Sails manufacture around 40,000 sails per year from our modern factory in the far east. Posted on 2 May Oyster Yachts announces the Oyster 805
A superyacht inspired bluewater cruiser Oyster Yachts has announced the latest addition to their fleet, the Oyster 805. Posted on 2 May Meet the Grand Soleil Blue
The ultimate weekender with a sustainable build Grand Soleil Yachts has taken its first step on a new path with the launch of its first true weekender, the Grand Soleil Blue. Posted on 30 Apr OOC delivers $133 billion for ocean action
Urgent challenges remain to meet global deadlines in a pivotal year for the ocean The Our Ocean Conference (OOC) has mobilized $133 billion in funding for ocean action over the past decade, according to a new report launched today by World Resources Institute (WRI) to mark the conference's 10th anniversary. Posted on 29 Apr Ella Hibbert starts Solo Arctic Circumnavigation
A record-breaking voyage to spotlight a vanishing Arctic British sailor embarks on a record-breaking voyage to spotlight a vanishing Arctic and spark global climate action. Posted on 29 Apr MMAG calls for vigilance and reporting
Seasonal alert and call to action survey for all mariners and offshore sailors As spring awakens in the Northern Hemisphere, a powerful migration is under way - not just of boats returning north from winter sailing grounds in the Caribbean, but of whales traveling thousands of miles. Posted on 29 Apr A look inside the Spirit Yachts yard
A close look at what makes their yachts unique Traditional skills in boatbuilding could be regarded as a lost art from a bygone era. In the world of fibreglass and carbon, the joinery and laminating techniques of wood ribs and cedar strips are a thing of the past. Posted on 28 Apr 85th Anniversary of Operation Dynamo drawing near
Preparations are progressing well for the sailing from Ramsgate to Dunkirk The date for the Association of Dunkirk Little Ships (ADLS) fleet sailing from Ramsgate to Dunkirk is drawing ever nearer, and preparations are progressing well for this, the Dynamo 85 return. Posted on 27 Apr Grand Soleil Blue: Finally in the water
Designed for those who want to enjoy sailing in total independence The official video of the Grand Soleil BLUE is now online: a yacht that redefines the concept of contemporary sailing: free, spontaneous, elegant, and sustainable. Posted on 26 Apr