Sir Ben Ainslie has paid tribute to Andrew Simpson, who died on Thursday while training with the Artemis Racing team in San Francisco Bay.
Simpson passed away after being trapped under his AC72 catamaran when it nosedived, capsized and broke into pieces.
Ainslie, who, as helmsman with Oracle Team USA, had been preparing to compete against Artemis Racing in the America's Cup, released a statement on his website.
It read: "This is such a tragedy. Andrew was such a wonderful husband, father, friend and one of the nicest people you would ever meet.
"The only solace I can find is that he died doing something which he loved. I have such fond memories of growing up sailing together as kids and then as adults.
"I will miss him so much. My thoughts and prayers are with Leah, their two boys and their family."
Simpson won Olympic Star gold in Beijing in 2008, before claiming silver at London 2012.