The event will take place in the river Guadalquivir, along a 2,5 Km course (two or four laps depending on the event 5 or 10 Km). The course will increase from 2,5 Km loop to 5 Km loop for the 25 Km competition on 8th May 2008. Competitors will swim in anti-clockwise direction, keeping the turn buoys off their left shoulder. Water temperature will be approximately between 24-25º C. Start & finish will be adequately marked in the Rowing-Canoeing High Performance Centre. The course is between 3 and 8 meters deep.

Automatic timing equipment is to be used for the timing of the competition. In accordance with FINA Rule SW11, microchip transponder technology has been added to the equipment. It is mandatory for all competitors to wear microchip transponders on their wrists throughout the race. If a competitor loses a transponder the coach will immediately inform the referee who will instruct the responsible official on the water to issue a replacement transponder. Any competitor who finishes the race without a transponder will be disqualified.

The dive start will be the official start for all events at the 5th FINA World OWS Championships Seville 2008.

There will be one feeding pontoon for the 10 Km event, located in the centre of the course and allowing support staff to feed the swimmers on both sides. Coaches pontoon accreditation bracelets (only one per participant swimmer) will be given to access onto the feeding pontoon during the competition. Transportation will be given by boat, and support staff will not be shuttled back to shore until the race is completely finished.

Notice that no boats will be allowed on the course other than official boats. No escort craft will be used for the 25 Km competition. For this event there will be 2 feeding stations: one of them located in the same place as for 10 Km race, and the second 600 m before/after the first turn, making possible to feed the swimmer each 1.250 m. Each entered athlete in 25 Km event can name two trainers (one for each platform). No coaches will be allowed onto the feeding stations without accreditation bracelets. In 25 Km race, only if it is an urgent need and always giving priority to the event safety, there will be a boat to take them to land.