Monique Gladding has insisted that she could not have put any more effort into her performance in the women's 10m platform event last night.
The Team GB diver, who has been struggling with neck problems since sustaining a serious injury last year, had to undergo a late fitness test to ensure she could compete.
Errors on two of her dives saw Gladding finish in 19th place with a score of 301.45, less that seven points short of qualification.
She told BBC Sport: "I've had problems with my neck since my accident and it really flared up quite badly. It was touch and go whether it was safe to dive.
"I've been in tears throughout the last week, but I couldn't have given any more."
Gladding's fellow Briton Stacie Powell also failed to make the semi-final, finishing in 20th place with a score of 287.30.