Prince William took to the water for the Scottish national universities side in the annual Celtic Nations sports event in Cardiff in April 2004.
Measuring 1.90 metres (6 feet and 3 inches), William was resplendent in black and grey Speedos and blue cap, tried his best on being called to the pool as a second-quarter substitute but was unable to stop his side losing 14-7 to the Irish side.
William, captain of the water polo side at St Andrew's University in Scotland, was not among the scorers but did win a particularly big cheer for helping prevent an Ireland goal.
His side also lost to Wales in their second and final match, losing 15-6.
William arrived at the Welsh Institute of Sport wearing faded jeans and scruffy trainers. He then had to force his way through a crowd of young leotard-clad female gymnasts who had just completed their event.
William won a place on the national university water polo team after competing in a trial at the council-run Carnegie Leisure Centre in Dunfermline, Fife. It was reported that he was offered private changing facilities when he arrived at the trials with a bodyguard but insisted in using the main changing rooms.
A spokeswoman for William said: “It is something he is delighted to be part of and he is pleased to be selected.