On only his second day in the Royal Navy the 25-year-old Prince was asked to wield a sledgehammer to release a cable attached to an anchor on HMS Hindostan, a training ship, at the Britannia Royal Naval College in Dartmouth, Devon.
Using all his polo skills, William tapped the metal release mechanism – and groaned as nothing happened!
Looking somewhat nervous and embarrassed, he tried again and 30 meters of cable and the anchor slipped effortlessly into the River Dart.
"That's a crate of beer." William told reporters.
Petty Officer Wayne "Rats" Rattenbury explained it was a Naval tradition for those who had failed at the first go to buy their crewmembers drinks. "It could have been worse – 16 blows is the worst ever," he said.
Earlier William showed remarkable skills at the wheel of a 14-meter-long Picket boat, a training craft.
Under the watchful eye of Chief Petty Officer John Binks, the Prince spent more than half an hour cruising up and down the harbor practicing berthing and turning maneuvers.
Gaining in confidence, he drew alongside the larger Hindostan, performed a 180 degree turn, and triumphantly sounded his horn. Looking proud of his achievements, William leaned out of the cabin and said to his crewmates: "How was that?"
Looking tanned from his recent vacation on Mustique in the Caribbean with girlfriend Kate Middleton, William wore a blue beret and "number four" working uniform.
After a month's training, he will spend 5 weeks aboard HMS Iron Duke in the Caribbean looking for drug smugglers and possibly helping hurricane victims.
William's two months in the Navy forms part of his preparations to become head of Britain's Armed Forces as King.