William and a group of his friends were turned away from the Seacroft restaurant in Wales on Sunday night because the establishment didn't have room to seat about 20 additional guests.
"The plan was to eat there, but unfortunately they had one of their chefs off sick so they weren't able to cope with the number that we had brought," the operational commander of William's unit, Squadron Leader Iain "Spike" Wright, said. "And so we found another location and we moved on."
A local businessman, Jonathan Campbell, 39, said the restaurant phoned the nearby Treaddur Bay hotel to see if they could take the party.
"They thought it was a joke that it was Prince William and his buddies and they had to ring three or four times and say 'no, this is real,"' he said.
But Campbell said he was not surprised the party was turned away from the Seacroft.
"We've got to pre-book, he's got to pre-book," he said. "So it's only fair."
Although residents weren't surprised, Marianne Swanner, an engineer visiting from Orlando, Florida, was shocked.
"In the States, if (President Barack) Obama wants to go there, they'd have let him," she said. "They would have cleared it out and let him in."
The restaurants are near the Royal Air Force base where William serves as a helicopter search and rescue pilot.
