Dame Ellen MacArthur and Olympian Matthew Pinsent were among the sailing superstars who were out in strength on the River Thames on Monday.

The iShares Extreme 40 catamaran and its crew hosted some of the world's top sailors as they competed to set the fastest time on a course from Greenwich Yacht Club to the O2, and back.

The event was part of the celebrations marking Greenwich Yacht Club's centenary.

iShares is one of twelve Extreme 40 teams that are competing this year for the iShares Cup in five international regattas held throughout Europe.

Extreme 40 catamarans have two 40 ft hulls and a 62 ft main mast, all made of carbon fibre. They are one of the fastest sailing craft ever built and can reach a speed of 40 knots (46 mph).

The same crew stayed aboard the iShares boat throughout the event. They were joined by representatives from three other teams who took turns to command and steer the boat.

Dame Ellen MacArthur and Matthew Pinsent were the first two out on the water, representing BT and iShares.

Next up was Pete Cumming, skipper of Oman Sail, a team supported by the Sultanate of Oman.

Fourth to go was Rob Greenhalgh, the 2007 Extreme 40 Champion, representing the British America's Cup entry TEAMORIGIN.

The course went through a start line outside Greenwich Yacht Club and the Extreme 40 sped towards the O2 in to an oncoming westerly wind. The clock stopped when it crossed a line outside the famous venue, where it turned and completed a second timed run sailing towards the Thames Barrier. The two times for each competitor were added together.

Working life on the river continued, creating some novel hazards. At times the Extreme 40 had to steer a course to avoid tugboats towing steel barges upriver.

Results 1. Pete Cumming, Oman Sail, 9 minutes 14 seconds 2. Matthew Pinsent, iShares, 9 minutes 28 seconds 3. Dame Ellen MacArthur, BT Team, 9 minutes 57 seconds 4. Rob Greenhalgh, TEAMORIGIN, 10 minutes 6 seconds.

We asked Matthew Pinsent if it had been a lot of fun. "That wasn't fun," he replied, "that was awesome."