Simpson, 36, a two-time Olympic medalist and father of two young boys, suffered multiple blows to his head and body in the May 9 accident involving the 72-foot Artemis Racing catamaran, the San Francisco Medical Examiner’s report said.
In the moments before it capsized, the yacht was turning downwind in a so-called bear-away maneuver in normal conditions, while traveling at about 30 knots, or 34 miles per hour, with wind of about 20 knots, or 23 miles per hour, the report says.
The front of the vessel then dipped beneath the surface, the port hull broke and inverted on top of the wing, according to the report. The precise sequence of events was not clear from the report, nor did it explain why Simpson was unable to find his way out.
Simpson was wearing a helmet, wetsuit, flotation device and shoes when he was trapped for approximately 10 minutes beneath the high-tech yacht.
Four chase boats helped the other 10 crew members off the crippled sailboat, the report said.
“But the subject remained trapped for approximately 10 minutes,” it said. “The subject was then located, floating in the waters of the bay, unconscious.”
A toxicology report found that the only drug in Simpson’s system at the time of his death was caffeine.
The Artemis yacht, which some have said was problematic from the start, was to have been retired on the day it capsized.
The accident at one point threatened to scuttle the famed sailing regatta, but racing continued after a number of rule changes were made, including substantial reductions to the wind limits. Oracle Team USA successfully defended the trophy with a dramatic come-from-behind win over Emirates Team New Zealand.