PRINCE WILLIAM described the devastation in Christchurch as ''unbelievable'&ap os; during his tour of the earthquake zone yesterday.

Just before 1pm, the Prince entered the red zone, travelling up Gloucester Street and stopping at Cathedral Square.

An Urban Search and Rescue engineer, Des Bull, and the Reverend Peter Beck were among those to meet Prince William at the site of the ruined ChristChurch Cathedral.

The Prince then travelled down to Latimer Square. Outside the square, Mr Bull told Prince William about the damage to the leaning high-rise Grand Chancellor hotel building in the central business district.

''It's just the scale of it, it is unbelievable,'' the Prince said.

''It really does bring it home to see it leaning like that. When you see buildings like that … that's very, very sad.''

Inside Latimer Square, Prince William was greeted by dozens of rescue workers. ''You guys have been doing a sterling job. You really have. You have done fantastically well,'' he said.

The Prince also spoke of how it had been an ''horrendous time for disasters in the last six months''.

''There was a lot of us who were in the military were gnashing our teeth to get over here,'' he said of the situation in Christchurch.

The search and rescue area commander, Steve Barclay, was among those who spoke to the Prince. ''It's a great morale booster to have him here. It's not purely symbolic. We had Russell Crowe here the other day and we had John Key, and having the Prince come all this way to acknowledge our problems is a real morale booster and we really appreciate it.''

The Prince also spoke to Shane O'Brien, another rescue officer, whose house in Bexley was damaged by the earthquake.

''While New Zealand is a tiny little place in the middle of nowhere, it's nice to know the world knows where we are and who we are,'' Mr O'Brien said.