Ainslie has represented Britain in four consecutive Optimist world championships, latterly as a member of the national squad now coached by Jim Saltonstall.
In the Laser 1 world championship, Nik Burfoot, a Kiwi sailing for Britain who was leading the fleet of 99 with two races remaining, slipped to fourth overall behind the winner, Finland's Thomas Johanson.
With less than 3,000 miles to Cape Horn, the pressure is mounting on the 85ft catamaran, Commodore Explorer, skippered by Bruno Peyron, who are well into the second half of their attempt to sail around the world in 80 days to win the Jules Verne Trophy. Peyron is ahead of schedule and could beat the target by two or three days.
With under 100 miles to go, skipper Mike Golding and the crew of Group 4 are expected to cross the finishing line in Cape Town today of the third leg of the British Steel Challenge.Reuse content