BOATMAN Jack Allen got the surprise of his life yesterday when he found his punt customer was former US President Jimmy Carter.

The 19-year-old took the 83-year-old Nobel Peace Prize winner and three companions for a trip on the River Cherwell, near Magdalen Bridge.

The former President is staying in the city for a few days after receiving an honorary degree.

Gap year student Mr Allen, from Stratford Street, East Oxford, found himself flanked by three punts containing armed US Secret Service agents throughout the 30-minute cruise.

But he managed to remain calm enough to steer and chat.

Mr Allen said: "It wasn't nerve-wracking, but you did have a sense of presence.

"I was just very conscious and tried to interact with him as much as possible - and was pleased at how down to earth he was."

Mr Carter was with his wife Eleanor and two people believed to work at Mansfield College.

Sights on the tour include St Hilda's College and the nearby Botanic Garden, and the party eventually stepped off at 3.45pm.

Jack, who received a bottle of Champagne from Mr Carter for his efforts, said: "He said the river was very peaceful and they joked about this being the student life.

"He was very pleased to be recognised and posed for photos. At one point, he fed a strawberry to one of the ducklings, which was quite nice."

Andrew Howard, owner of the Magdalen Bridge Boathouse, which runs the tours, said he had first been approached months ago, but kept the rest of his crew in the dark until Mr Carter turned up .

Mr Howard said: "I was a little nervous but I have been here for 25 years and you get used to that."

Celebrities including Pierce Brosnan, Rik Mayall, Michael Portillo and Chris Tarrant have previously been on his tours.

A group of American tourists failed to spot Mr Carter - one of three surviving former Presidents - despite the presence of at least six security guards with earpieces. When informed of the ex-president's visit, one said: "JC was here? I love that guy. Don't tell anyone we missed him."