It is possible to sign up for the annual naturist race on Sopelana's Barinatxe (La Salvaje) beach today until up to half an hour before its scheduled start at 12pm to coincide with low tide.
Entrance is free and there are a number of categories according to age and sex.
Adults will race over 5,000 metres while under-14s are only required to cover half that distance.
Afterwards, all participants are invited to lunch at the Golfo Norte restaurant in Barrica.
The event is being organised by the Basque Naturist Association.
Today's forecast of cloudy skies and light rain indicates near-perfect, though slightly chilly, racing conditions.
Record turnout for nude beach race
Sunday, September 16, 2007
A total of 136 men, women and children took part in the annual Sopelana nude race yesterday on Barinatxe Beach. Organisers said that the continued good weather was a major factor in achieving the highest turnout since the event was first staged in 1999.
45 men, 10 women, 65 veterans and 16 minors, including the youngest competitor - a 6 year old girl from Bilbao - lined up for the start of the race at 12.30pm.
The 2.5km junior race was won by 11 year old Mikel Rodríguez from Erandio in a time of 10 minutes, 31 seconds.
First place overall in the main 5km race went to last year's champion, Fernando Suances, in a time of 18 minutes, 21 seconds while Patxi Ros won the men's nude race (20 minutes, 8 seconds).
Mercedes Cura won both the overall women's event and the women's naked race in a time of 24 minutes, 30 seconds.
The veteran's race was won by Juan Carlos Zamorano in a time of 19 minutes, 9 seconds.
As well as trophies, the winners were awarded prizes including week-long stays at nudist colonies in Gran Canaria and Almería.