Editor's note: Shirley Robertson is the presenter of CNN's Mainsail and she was also a good friend of Simpson. She made history by becoming the first British woman to win two Olympic Gold Medals at consecutive games, Sydney 2000 and Athens 2004.
(CNN) -- The sailing world is reeling after Briton Andrew "Bart" Simpson's tragic death on the waters of San Francisco Bay while training with Sweden's Artemis America's Cup team on board a boat that is about as extreme as it gets.
It's unbearable to think what his family and those closest to him are having to face up to.
Bart was a lovely 'gentle giant' of a man who I have so many fond memories of inside the British Olympic Sailing team.
For years he had lived in the sporting shadows of his great sailing friends Ben Ainslie and Iain Percy.
But in the last two Olympics, while sailing with Percy, Simpson won Gold in Beijing then Silver at London 2012.
In San Francisco "Bart" was with Percy as part of a 11-person crew on board what would have undoubtedly have been the most radical boat that either of them have ever sailed.
The huge AC72 multihulls have been introduced to take the oldest trophy in sport to a new era. These boats' masts are 130-foot high -- more than 20 times the average height of the 11 crew.
"I really love these boats because they are very physical, they're very dynamic, they're fast, exciting and the racing is very close," Ainslie -- the most successful yachtsman in Olympic history -- recently told CNN's Human to Hero series.
"The top speed of these boats is around about 30 knots, or 35 miles an hour, which is pretty quick when you're that close to the water."
The America's Cup is the elite competition in yachting that is funded by billionaires and traditionally dominated by the U.S. since it started in 1851.
Teams from only four nations have won it: the United States, Australia, New Zealand and Switzerland. The New York Yacht Club held the cup for well over a century.
Yet it is no longer a tactical game of chess on water in relatively slow yachts; it is now a full on physical battle with an immense machine, and the forces of nature.
The boats are spectacular to watch and sail. Some can fly over the water on hydrofoils and all are powered by giant wings.
The crews who sail them talk openly about the danger and hard hats, body armor and personal air bottles are all part of their sailing gear.
On the water support boats stay close in case they are needed to react quickly to an incident. But as we saw so with "Bart", risk cannot be eliminated.
After a catastrophic incident -- the details of which no doubt will emerge with more clarity over the coming days -- Simpson was trapped underwater and, despite valiant efforts to save him, lost his life.
Before this tragedy words like "danger", "extreme", "on the edge" seemed part of the appeal of this edition of the America's Cup. But in the light of Simpson's death it's hard to not read the same words in a different light.
I am sure that all aspects of the safety of the race crews will be reviewed intensely, but risk can never be removed.
I am equally sure that some will feel that these boats have gone a step too far while others insist that sailing is a technology sport and that this is a competition where that technology must be allowed to develop.
Ultimately it's so desperately sad that a combination of circumstances that the sailing community knew could happen, did happen.
And that the 36-year-old Simpson -- an understated, hugely talented sailor -- lost his life.