Harrowing footage filmed on a mobile phone shows a woman scream "you're going so fast" to her date shortly before she died in a speedboat crash on the River Thames.
Tragic Charlotte Brown, 24, filmed the clip on a boat owned by Jack Shepherd, 30, from Hammersmith.
Moments after it was taken, Charlotte took the wheel of the vessel, and the pair - who had both been drinking - were thrown into the water when the boat hit a tree trunk.
She died as a result of her injuries.
He was found guilty of her manslaughter today (Thursday, July 26) and is now on the run having failed to turn up for his trial.
Her family have pleaded with him to attend court to face sentence.
Katie Brown, the victim's sister, said in a statement on behalf of the family: "The immense pain and anguish we feel will never pass and our grief will last a lifetime."
She continued: "Charlie died because she thought she would be safe taking a journey on Jack Shepherd's speedboat - a speedboat that we know was unsafe and that he bought with the sole purpose of seducing young women and one he had used recklessly many times before.
"During the trial, in his absence, with his whereabouts unknown to both the court and police, Jack Shepherd was afforded more rights that Charlie.
"Throughout this trial we have been appalled by the tactics the defence have stooped to to protect their client in his absence - a particular lie for our family was when the defence said that wearing a life jacket would not have saved Charlie's life.
"As a family, and as testified by experts, we firmly believe that Charlie would not have drowned if she was wearing a life jacket."
Shepherd was not in court for any of his trial, and a warrant has been issued for his arrest.
Katie Brown added: "We now appeal to Jack Shepherd wherever he is in the world to return and assume the responsibility of his guilt and the devastation he caused by his actions that fateful night - we appeal to Jack Shepherd's family and friends to appeal to him and urge him to face the consequences of his actions."
Ms Brown said the family now planned to work with the Royal National Lifeboat Institution to tighten the legislation on the UK's waterways to prevent further tragedies.
Web designer Shepherd had been trying to impress Charlotte after meeting her on dating website OkCupid.
But their champagne-fuelled first date ended in tragedy when his boat capsized and she was thrown into the river in December 2015.
Shepherd had denied manslaughter by gross negligence but was found guilty in his absence at the Old Bailey.
It can now be reported that he skipped bail and failed to attend his trial, to the anger of Ms Brown's grieving parents in court.
Despite issuing instructions to his legal team by phone, police were unable to track him down and his whereabouts remains unknown.
The court had heard how Shepherd had bought the 14ft Fletcher Arrowflyte GTO from Gumtree to "pull women".
In the months before Charlotte's death, he had entertained up to 10 women on the boat, having invited them back to his houseboat in Hammersmith.
During that time, he had been caught speeding by marine police more than once and advised on the importance of wearing life jackets.
A previous date, Amy Warner, told jurors she felt so uncomfortable aboard the vessel that she asked Shepherd to slow down and then got a taxi home.
On December 8, 2015, Shepherd treated Charlotte to a £150 meal at Oblix in The Shard, where they drank two bottles of wine.
The couple took a taxi back to Shepherd's place where they took champagne aboard the speedboat for a trip past the Houses of Parliament.
In the mobile phone footage, Charlotte can be heard shouting that they were going "so fast" as Shepherd drove at more than double the 12 knot speed limit.
On the return journey, Shepherd handed over the controls to business development consultant Charlotte who followed suit and went "full throttle".
Moments before the accident, Charlotte's sister texted her: "Is he driving this bad boy?" but received no answer.
The speeding boat hit a submerged log and tipped over near Wandsworth Bridge, sending both occupants into the water.
Riverside resident Steven Morrissey told the court that he heard a young man screaming for help.
He said in a statement: "He kept saying 'Help me, help me, somebody help me'. It was just 'Help me' - not 'us', or 'her'."
Shepherd was found clinging to the hull and Charlotte was pulled from the water unconscious and unresponsive.
Paramedics battled in vain to save her as she was already in cardiac arrest and suffering from hypothermia.
The next day, Shepherd tearfully told police that he had taken Charlotte out on the river as part of his seduction routine.
He said: "I was just trying to show off about having a speedboat like I thought it would impress her."
Shepherd told police Charlotte was going "full throttle" when they crashed.
He said: "My memory is quite hazy about the whole thing because we drank heavily.
"I had no idea what happened. I was hanging on and tried to go underneath the boat to see if she was there and got trapped.
"I was feeling with my legs to see if she was there. I don't think she was there but I didn't know. I just started shouting for help, 'please help, please help'."
Prosecutor Aftab Jafferjee QC told jurors: "It was cold, it was dark, we submit, it was sheer madness."
The jackets had been tucked away, the kill cord was not connected and the boat had a number of defects, including faulty steering, the court heard.
Jurors were told the defendant denied manslaughter on the basis he had no "duty of care" towards Charlotte.
It can now be reported that Shepherd told his lawyers in mid-May he would not attend his Old Bailey trial in July but the Crown Prosecution Service and court only found out a week before.
In legal argument, the prosecution said police had spoken to his mother on June 27 and were told he had not been in contact since March and his phone number was no longer connected.
His defence team insisted they did not know where he was even though his solicitor had maintained telephone contact.
It later emerged he had been receiving daily updates from the trial from his legal team.
But they successfully argued that the reason for his absence should be kept from jurors deciding his case and they should only be told he was not in the dock and had "chosen" not to given evidence.
Mr Jafferjee said the lawyers had been "dancing on pins" as they debated exactly what to tell the jury, as the defence objected to the words "failed to attend".
Shepherd is also wanted by police for failing to attend court over another unrelated matter.
Following the verdict, Judge Richard Marks QC, the Common Serjeant of London, read out a note passed to him by the jury reading: "We are concerned that the current lack of licensing regarding private boat ownership on the Thames and lack of clarity regarding safety matters greatly increases the risk of further incidents."
It continued: "[We] would hope that the result of this case will lead to a high level review of matters going forward."
Shepherd will be sentenced at 11.30 on Friday morning.
