Young America was designed strong enough to withstand the pounding seas on Auckland’s Hauraki Gulf in the Louis Vuitton Cup challenger yachting series, co-designer Russell Bowler says. He yesterday pointed to construction problems and inadequate repairs made to the boat a week before it broke up and almost sank during racing on November 9.

Bowler revealed Young America’s first boat, of the same name as the syndicate, had demonstrated structural problems for two months before the break-up. Bowler, who helped design the boat along with his partner, New Zealand-born Bruce Farr, said USA53 had delamination problems since its launch in September. Delamination occurs when the skin on the hull does not bond correctly with the carbon fibre core. That is a construction problem.

Bowler said his reaction to the near-sinking had been one of “utter horror” because he had been convinced the side-deck design of USA53 had been strong enough. “Contrary to a lot of speculation, the design was not marginal or light in this area, but in fact had adequate material to resist the given loading.” Bowler said the side-deck, where the boat later broke, had a particularly thick skin in order to ensure it was strong enough, forwards and backwards, to carry the loads from the rig. But he said it appeared a repair carried out a week before the break had been inadequate.

He said neither Farr Yacht Design nor the original boat builders had known about that repair. Bowler said Young America would work with International America’s Cup Class (IACC) technical measurer Ken McAlpine to consider whether the design and construction rules needed to be altered to reduce the risk of boats breaking. But he said IACC boats were like Formula One racing cars and could be fragile. That was why it was up to designers to ensure boats were strong enough to withstand sea and wind conditions.

Bowler said Young America had raced and practised in big seas without problems before November 9. Bowler said Farr Yacht Design issued a statement yesterday on the cause of the problem to prevent speculation about what caused the breakage and criticism of the design company. He said Farr Yacht Design was disappointed Young America had not released their updated findings on the breakdown, which included the report of an independent insurance examiners.

Bowler spoke to reporters from Farr’s base in the United States as race three in the Louis Vuitton Cup finals was abandoned because of a lack of wind on the Hauraki Gulf. Prada and AmericaOne each have one win in the best-of-nine series.