Crews from at least 10 yachts saw or heard an accident that killed five people, but no one stopped to help.

That’s according to a report looking into the Full Crew Farallones Race, held off the coast of San Francisco in April this year, when five sailors drowned.

The report by a US sailing association independent review panel blamed the captain for the fatal capsize, concluding that an unsafe course left the yacht exposed to “larger than average” breaking waves.

The report also states that some of the sailors who died weren’t wearing sufficient safety gear. Two survivors told investigators that some of the crew might have been saved if they’d taken better safety precautions.

“If they had been clipped in, the majority would have been okay, but bruised,” said survivor Bryan Chong.

The report said that communication and race-management problems hampered the rescue, adding that nearby boats could have provided aid by signalling with those on shore, searching for those in the water, or providing continuing relays for radio communication.

“The panel found it troubling that no boats appear to have dropped out or delayed their race in order to render assistance, which is a basic tenet of the sea, as well as the first fundamental rule of the racing rules of sailing,” the report said.