The coach who was with Susan Taylor when she died swimming the Channel, said that "total fatigue" was the cause.
She had been swimming for more than 16 hours, covering 30 miles, when she collapsed in the water.
Donations to the charities for which she was fundraising have passed £60,000.
ITV News correspondent Juliet Bremner reports:
Susan Taylor's brother David Wright offered a moving tribute to his sister saying that he hoped her dedication would inspire others.
"We hope that Susan's dedication to promote these very important charities will encourage others to look beyond themselves and continue what she held so dear," he said.
The charity donations for Susan Taylor, a swimmer who died while attempting to cross the English Channel, are now over £59,600.
Mrs Taylor was raising funds for Rainbows Children's Hospice and Diabetes UK.
Susan Taylor's coach Paul was close to tears as he offered an emotional tribute to her as a 'natural giver'.
As he held back the tears, Susan Taylor's coach said she was a "natural giver", adding that the decision to help her had been a "no-brainer".
– Susan Taylor's coach
Her commitment to her training meant that she had put on hold her career as an accountant so that she could give, because this was what Susan was really about.
She was a natural giver. So when Susan approached me two years ago and asked me if I would be so kind as to help her on her journey - she told me that she was swimming for charity, the Rainbows Hospice charity based in Loughborough, my home town.
Having taught children with severe learning disabilities myself for a short time, the answer was a no-brainer.
The coach of Susan Taylor, who died in a charity swim across the Channel, said in a press conference that she was "always smiling".
He said: "Susan was always smiling and was fully enthusiastic, whilst never being a champion. I could always rely on her physical strength to give 150 percent.
"She was a very big team player."
The charity pages for Susan Taylor, a charity swimmer who died while attempting to cross the English Channel have now reached over £47,600.
Mrs Taylor was raising funds for Diabetes UK and Rainbows children's hospice.
Donations have rocketed since news of Mrs Taylor's death.
Donations have poured in for Susan Tayor, a charity swimmer who died while attempting to cross the English Channel.
She was pulled from the water and on to a support boat by her brother David, a paramedic, who battled to save her life before she was taken to hospital in nearby Boulogne-sur-Mer, where she was later pronounced dead.
More than 2,000 people have now donated to Mrs Taylor's fund-raising page as the current total raised soared to more than £42,500.
David Walliams has tweeted about Susan Taylor's attempt to swim the English Channel describing her death as a "tragedy".
Susan Taylor's channel swim attempt very sadly ended in tragedy. This is her charity page if you want to donate... http://t.co/US483gQNWw
The comedian swam the Channel himself in 2006 raising hundreds of thousands of pounds for charity.