Fi Fairbairn set out from the Makarora end of the lake before dawn, planning to swim the 45km to Roys Bay in about 15 hours.
However, in choppy lake conditions, close to Stevensons Arm, Ms Fairbairn was lifted into her support boat, taken to the Wanaka Yacht Club, where she was transferred to an ambulance and then driven to the Wanaka Lakes Health Centre for a check-up.
Members of her support crew could not be contacted last night, but the Wanaka Sun reported earlier Ms Fairbairn had twice previously swum part of the length of the lake in a relay.
Yesterday’s swim raised $3000 for the Darryl Fairbairn Memorial Fund, which is used for youth counselling through community networks.