In 1894, William K. Vanderbilt came for the second time to see Nathanael Herreshoff to commission a new defender to race the America's Cup against Valkyrie III the next year.
Vanderbilt was believing in Herreshoff's genious and gave "carte blanche" to the 'Wizard of Bristol' to build the New-York Yacht Club's next challenger.
Herreshoff reminded his previous bad experience when Vigilant's sliding centerboard had jammed and hindered his boat: he decided to build Defender with a fin keel.
The yacht was designed in the utmost secrecy and her construction was shrouded in mystery. Nobody was allowed to enter the yard and Captain Nat certainly did not appreciate the press and photograhers.
In building Defender, the Hereshoff brothers' special innovation was the use of aluminium. But as from the first tests, the boat suffered from a phenomenon about which little was known at that time: corrosion due to electrolysis appeared after she was launched on June 23rd, 1895. America's Cup 1895: at the 9th challenge, Defender beated Valkyrie III and won the Cup.
