Wellington  - Pam Dickson, a 55-year-old grandmother, has become the oldest person to swim the 26-kilometre Cook Strait separating New Zealand's North and South Islands, a news report said Saturday.

She completed the crossing from north to south on Friday in 9 hours and 23 minutes, Radio New Zealand reported.

Her guide, veteran Strait swimmer Philip Rush, said it was a "great effort" by the massage therapist and marathon runner at her first attempt on the notoriously tough stretch of water in gusty winds that made conditions difficult for her and the support crew.

The youngest swimmer to make the crossing was 11-year-old Indian Aditya Raut, who completed the swim in 9 hours 9 minutes in February 2005. (dpa)