Nina Wilde, from Illogan, spent an hour underwater in the swimming pool at Redruth School in memory of her father Andrew.
Mr Wilde died in a diving accident in August 2002, when she was just two years old. It was a traumatic time for Nina's mum Esther, coping not only with his death, but the fact that his body was never found.
At the time of the tragedy, Mrs Wilde was contacted by the Fishermen's Mission. Although Mr Wilde had never been a fisherman, the organisation gave her its full support. When Nina was old enough to understand, her mum told her about the kindness shown by the Fishermen's Mission and the 11-year-old vowed to return the favour.
As soon as she was old enough and skilled enough to complete a solo dive, she set up the sponsored event at Redruth. She raised money in advance of the dive and also collected coins thrown in to the pool during her hour underwater.
Mrs Wilde said: "Nina came up with the idea herself. As soon as Brendon Rowe, her diving coach, thought she was good enough to stay under water for an hour, he let her do it."
Mr Rowe, Peninsula Sub Aqua Club's diving officer, said: "We were more than happy to get involved in this tribute to Andy. Nina did fantastically on the dive and it is great that she has raised this money for such a worthwhile cause."
Nina visited the mission at the weekend and presented £855 to regional manager Gina Moore.
Mrs Moore said: "We were extremely impressed with Gina's efforts. She raised such a lot of money in memory of her father, and yet she's only 11.
"We are absolutely delighted with her efforts and most grateful to her and to her mum, her school and the members of diving clubs who supported her."
article copyright THE CORNISHMAN