A brother told an inquest of the harrowing moment he had to leave his sister to drown after they were washed into a water-filled cave.
Alex and Charlotte 'Buffy' Furness-Smith, 30, had been coasteering when they became trapped in an inlet by a 15ft wave at Tilly Whim Caves, a Dorset beauty spot.
Alex, 31, decided to swim for help after being unable to raise the alarm.
He told the Bournemouth hearing: "Buffy wanted to go with me. She said she could not bear not knowing if something had happened to me.
"I said that she should be able to see me going out and if I did get into danger she would have a second chance of getting out. I asked her to stay put. I thought that was the safest thing to do."
He said that Charlotte, a former Royal Navy 'poster girl', was 'scared and terrified' and screamed 'get me out of here' to rescuers who spent two hours trying to free her in severe conditions.
After her death, Alex told a coastguard: "I shouldn't have left her. She should have come with me. I can't believe she has gone."
Her body has never been found after her death near Swanage, Dorset, on November 2 2013.
The coroner ruled that Charlotte had died by misadventure and he recommended a gallantry award for a volunteer coastguard who took part in the rescue bid.
The inquest was embroiled in controversy because Charlotte's parents refused to take part and denounced the proceedings as a 'farce'.
Speaking to the Evening Standard, Charles and Patricia Furness-Smith said the coroner had refused their request for an adjournment to allow three 'key witnesses' to attend.
And they claimed that a 'significant amount' of written evidence had been 'suppressed' by the coroner Sheriff Payne.
Mr Furness-Smith said: "There was about an hour from when rescue services arrived to when coastguard Ian Bugler risked his life and went down the hole.
"That was a monumentally brave thing to do, and we extend our heartfelt gratitude. But the hour is totally unaccounted for, and that is the sort of thing one needs to question in the inquest. Unfortunately, in my opinion, the coroner is not doing any of that."
He added: "We have been trying to get to the bottom of what went on, and are deeply disappointed in the coroner, who we believe has not really listened to our concerns."
His wife Patricia, 57, said: "We have had to battle so hard just to get some honesty and truth about what happened to our daughter in her final hours. We feel we have been let down by the judicial process. "If lessons are not learned, this is going to happen again."
The family are considering appealing the verdict.