THE VESSELS: The Great White Fleet seen from Devonport.

A North Shore Times article on plans for a United States invasion is part of a centenary exhibition on the Great White Fleet.

The New Zealand National Maritime Museum is commemorating the arrival of 16 United States battleships in 1908.

When the vessels came to Auckland in August 100 years ago New Zealanders thought the Americans were here to demonstrate their naval strength.

WILLIAM STEWART COLLECTION WARM WELCOME: The entrance to Queen St greets the Americans in 1908.

It was a significant occasion and the Kiwis welcomed their presence.

But a 62-page document said to be written by 24 officers suggests a more sinister motive behind the visit, one which was only revealed when the North Shore Times reported about it in July 2006.

United States president at the time Teddy Roosevelt sent the ships to show the world the United States Navy could operate globally at a time when America’s relations with Japan were becoming tense.

There were worries that if America and Japan went to war Britain would join the opposition because of a treaty signed in 1902.

This would bring involvement by Australia and New Zealand and turn Auckland into a base.

The United States report details intelligence gathered during the six-day stopover 100 years ago.

The plan names the Manukau Harbour as the best invasion point "in case the defences of Auckland Harbour proper prove too strong for a direct frontal attack".

It includes loading guns on Rangitoto to shell forts on the North Shore.

The document Naval War Plan for the Attack of Auckland, New Zealand, details the strength of Auckland forts and describes the size and number of guns.

Referring to the harbours in the North Island, the report says: "Any of them could probably be occupied with little or no opposition provided the attack was sudden."

Department of Conservation programme manager heritage David Veart says when he saw the document he was "astounded".

"It’s an extraordinary piece of information."

Mr Veart says the document is not spontaneous and seems to have been planned for a while.

"It was such an unexpected thing."

James Recknor, executive director of the Institute of Modern Conflict, Diplomacy and Reconciliation at Texas Tech University, will talk about the story of the journey at the New Zealand National Maritime Museum in Auckland city.

Dr Recknor has published the book Teddy Roosevelt’s Great White Fleet.

The exhibition from August 1 to 17 will include a collection of medals, photos and postcards from American historian William Stewart.

Dr Recknor’s presentation, The Great White Fleet – A Centennial Celebration, is on Tuesday, August 12, from 7pm in the Maritime Room at the museum, corner Quay St and Hobson St. Admission is $15