The day endurance swimmer Kim Chambers jumped into shark-inhabited waters, a seal was found with its head missing.
"I didn't tell mum that," laughs the New Zealander as she relives the scary moment when she took the plunge a fortnight ago.
Mustering her courage in the pitch blackness, Chambers farewelled her support crew - which included her mother Jo - and dropped into the swell at the Farallon Islands, a spectacular Pacific Ocean outcrop 50km west of San Francisco.
Besides dense seabird colonies on the rock stacks, great white sharks inhabit the Farallon waters, hunting for sea lions and seals.
The apex predators usually gather there in September. This year, as Chambers planned her marathon swim, conservation scientists on the islands reported female sharks had turned up a month early.
"I didn't know what was going to happen. I didn't know if I was jumping into the mouth of a great white."
She set off at 11.16pm on August 7. 17 hours and 12 minutes later, having battled violent sea-sickness, 4m swells, mental terror and near total exhaustion, the 38-year-old reached the landmark Golden Gate bridge.
As the tears rolled, Chambers knew she had swum into history as the first woman to complete the epic Farallones crossing.
"I got really emotional. It's about putting my mind and body to something...having control of the doubt and fear which floods your mind."
The 48km ocean stretch had been defeated by just four swimmers, all men. In late July, Simon Dominguez, Chambers' training partner, was forced out of the water 5km from his goal by a circling great white.
Dominguez was bleeding from the neck, an injury caused by abrasive salt water chafing his skin.
Chambers' darkest moment was becoming ill: "I'm thinking 'I've just chummed in the water.' Here I was trying to sneak through there and hoping the sharks didn't notice and I'm vomiting."
In the sea, she forced herself to push the fears aside.
"I kinda think it's the sharks' living room, not mine. I really feel like a guest passing through.
"I mean I'm not on a death wish or anything. I love my life. But I felt compelled to do that swim and I really wanted to be the first woman to do it."
Apart from the Farallones swim, Chambers is one of just six swimmers to complete the Oceans Seven Challenge, the marine equivalent of mountaineering's seven summits.
The challenge requires open-water swimmers to dig deep into their mental and physical reserves to conquer some of the planet's most demanding seas. The list includes Cook Strait, which Chambers crossed in March 2012 in 8 hours 26 mins.
Strict rules are enforced. Swimmers who touch support craft are disqualified. They can only wear togs and caps.
A proud Kiwi, Chambers' cap has a New Zealand flag.
Companions are allowed in the water, but cannot push ahead because that could draught a swimmer like a cyclist following the pack. To lessen numbing cold, swimmers slather themselves in lanolin.
For the Farallones, the support team included a trauma surgeon. One of the two chase boats had thermal imaging equipment to detect big fish.
As she churned through the night, Chambers says she watched luminescence fall like glitter from her hands as she cleaved through the water: "I feel like I'm an astronaut out there in the sea. "
In the weeks before a long swim, Chambers eats like a horse, packing on as much as 25kg for buoyancy.
In the water, Chambers gulps energy-rich fluids every 30 minutes.
On her historic swim, she lost much of her precious nourishment because she forgot to take off a sea-sickness patch worn for the two-hour Farallones boat ride.
The upshot was that she ended the swim severely dehydrated and needed four intravenous bags of fluids.
For nearly a week, Chambers was in a "mental fog " and worried about the state of her organs. To her relief doctors have said she's in good nick.
Remarkably, Chambers got into swimming only in October 2009 when recovering from a dreadful leg injury. Taking a tumble in high heels and pants-suit, she fell awkwardly on her leg. Within hours her right shin and foot ballooned.
Admitted to hospital, a surgeon told her she was barely 30 minutes away from losing her leg. She had four operations and faced the prospect of permanent disability. Chambers jokes that she "could have stayed on the couch and eaten cake all day".
Instead, she got into San Francisco Bay and untapped a passion for long-distance swimming. She clicks off the kms with the aptly named Dolphin Club, and belongs to the Night Train Swimmers, dedicated water marathoners who swim for charity.
One of three siblings, Chambers spent her childhood near Te Kuiti, where her parents Gerald and Jo have a farm.
Jo has been with her daughter on three big swims. Before the Farallones mission, the pair went to Grace Cathedral in San Francisco and prayed for safe passage. Said Jo: "I knew she could complete the swim. We really wanted to settle our minds."
Kim learned to swim at primary school in Piopio, before ballet claimed her time. She danced while at Diocesan and then King's College. Her next discipline was rowing, which she picked up at the Berkeley campus of the University of California.
A trained software designer, she had a Silicon Valley job until the accident forced her out of work.
For the past few years she has been with Adobe Systems. Clearly a hit with the software giant, she has been asked to address 6000 staff at a Houston gathering in October.
Chambers calls her achievement "Oceans Eight" and thinks the stars were aligned that day.
"I do these swims for myself and for charity. You are rolling the dice in a way. You're not in a shark cage or a wet suit," she said.
"When you stop you get cold and if there's a current you go backwards. There is no other sport like it."
Having accomplished what she calls "the riskiest swim in the world bar none", Chambers is weighing her options.
Her father wants his daughter to take up golf.
"I'm still in a state of disbelief," she told the Herald on Thursday evening.
"I'm looking out my bedroom window and I can see the Golden Gate Bridge and I'm thinking 'Did that really happen?'"