Andrew Simpson

The investigations into what happened last Thursday continue, and it will undoubtedly be weeks or months before we learn much more about the details, but what we know now is this: while practicing on the San Francisco Bay, just after 1:00 PM, the Artemis Racing AC72 "Big Red" capsized, and champion sailor Andrew Simpson died.

Wired summarizes the event:

Yesterday afternoon, both Artemis and Cup defender Team Oracle were on San Francisco Bay for a practice run. The teams stayed close together — they weren’t racing, but paying close attention to how the boats stacked up in similar winds. At 1 p.m., the boat neared the center of the triangle created by Angel Island, Alcatraz, and Treasure Island. During a bear away, the same common but tricky maneuver that led Oracle’s AC72 to capsize in October, Artemis’ boat went into a nosedive.

Although sailing is a very dangerous sport, it is an extremely rare occurrence for a top-level professional athlete to have a fatal accident while practicing his sport; it is hard to overstate what a shock it is for this to occur.

The Artemis Racing team is superb; they are well-managed and well-trained, they have the very best equipment available, and they are extremely careful about what they do. I'm biased, of course, since the team is located in my hometown, but I'm not lying: the best sailors in the world were out on the bay last Thursday, sailing the fastest boats on the planet in the best sailing spot on the planet.

But I've been out on the central bay at 1:00 PM on a May afternoon, and it can be a terrifying and intimidating place. In a great piece a few years ago, Captain Ray Wichmann of Olympic Circle explains the meteorology behind "the slot":

This San Francisco Bay summer wind is the result of a unique geographical phenomenon. At 38˚ north of the Equator, the Bay Area is in the path of the prevailing westerlies. This means that most of the time the wind comes from the west. Just 60 miles inland from the Bay is the Great Central Valley, with its extremely high summer temperatures. From Bakersfield in the south to Redding in the north, afternoon summer temperatures often reach 110˚F and sometimes even higher. This is the only place on earth that I know of where you can have a 50˚F temperature difference within 50 miles, without any elevation change. It can be 55˚F in San Francisco and, at the same time, 105˚F in Vacaville.

As this very hot air rises, cooler air is pulled in to replace it. The hotter the afternoon temperature in the Central Valley, the more rapidly the heated air rises and the stronger the inward air flow. The Sierra Nevada Mountains, a 10,000 foot wall to the east, make it unlikely the replacement air will come from that direction. There are, however, many low places between the Central Valley and the Pacific Ocean through which this inrushing air can pass easily. Only the Golden Gate, however, goes all the way down to sea level. Because of this, the Gate is the funnel for the primary source of replacement air for the Central Valley. Since air is fluid, it accelerates as it is forced to squeeze through narrow openings. As this cooler replacement air squeezes through the Golden Gate, it is accelerated directly down ‘The Slot, setting up the Bay’s exhilarating winds of summer.

The Independent reports that several investigations are underway:

The first will be led by the San Francisco police, who investigated an April 2012 accident in a race off California and Mexico, when four crew of a 37-foot Aegean yacht died.

A second investigation will be led by the America's Cup director of racing, the Australian Iain Murray, a former America's Cup yacht designer and skipper.

The San Francisco Chronicle includes some additional details about the Murray investigation:

"It appears Bart was trapped under some of the solid sections of the yacht," Murray said. "Unfortunately, they were unable to retrieve him, and he passed."

Murray said each crew member was equipped with oxygen, a helmet and an inflatable lifejacket. He said he wasn't sure what safety gear Simpson was using or if he was tethered to the boat at the time of the crash.

San Francisco officials said Simpson was stuck under water for about 10 minutes before he was pulled onto a support boat. There, city firefighters attempted CPR but were unable to revive him.

Nothing that can happen now will bring Simpson back, but I hope that the investigations will be productive, and lead to improvements in gear, in technique, in preparation, and, eventually, in safety. I'll keep an eye on these investigations to see how they turn out.