Image copyright AFP Image caption From spy ship to tourist attraction - the USS Pueblo is now run as a museum in Pyongyang

There is only one US Navy ship in the world held by a foreign nation - the USS Pueblo, a spy ship which was captured by North Korea on 23 January 1968. Its crew were held prisoner by North Korea for exactly 11 months before being released.

The ship is now moored in a river in Pyongyang and serves as a tourist attraction.

Guided tours are offered by officials who recount how the brave seamen of the People's Army thwarted the US imperialists by capturing the ship in "their territorial waters" - a claim always denied by the US, which says the Pueblo was well within international waters.

In early January 1968, disguised as a scientific vessel, the ship set sail from Japan carrying high-tech communications equipment and a crew of more than 80, many of whom were experts in decoding the messages they hoped to intercept from the North Korean military.

As long as the Pueblo stayed in international waters no one imagined that the North Koreans might try to capture it; so the crew were totally unprepared when the unthinkable happened.

Burning secrets

Image copyright Other Image caption Skip Schumacher was Operations Officer on the Pueblo when it was captured

The Pueblo was off the coast of Wonsan - North Korea's most active and largest cargo and military port - when a local harbour patrol vessel sent a message warning the crew that they should allow them to board.

When the Americans refused, the North Koreans opened fire.

"We didn't have anything to fire back with, the whole notion was that we were to be an unarmed trawler-like vessel; that was our disguise," recalls Lieutenant Skip Schumacher, the Operations Officer on the ship, who was 24 years old at the time.

They put a gun to his head and said: 'That's it, we're going to kill you' Lt Skip Schumacher, Operations Officer

The captain of the Pueblo tried to buy the crew some time by heading out to sea but the ship's maximum speed was only 15 miles an hour (24km an hour), and no match for the North Korean fleet.

The crew's main concern was to destroy all sensitive material on board before it fell into enemy hands, but without access to modern paper shredders, they had to burn documents in metal barrels or cans - a slow and painstaking process.

The North Koreans - understanding exactly what was going on - opened fire each time they saw smoke emerging from the ship.

In just over an hour, one sailor was dead and about a third of the crew were injured. The captain of the ship, Commander Lloyd M Bucher, decided he had no choice but to surrender.

The 'Pueblo Incident' Image copyright AP • The USS Pueblo is still an officially commissioned US vessel, and is one of the oldest in the US Navy • It is moored along Taedong River in Pyongyang • The capture of the ship came to be known as the "Pueblo Affair", the "Pueblo incident" or the "Pueblo crisis" • The Pueblo had two 50-calibre machine guns on board. They were on the deck, but there were strict instructions that they be covered at all times • The ship is named after Pueblo County in Colorado • There are still efforts to get the Pueblo returned. Over the years there have been a number of discussions between US and North Korean officials on the issue Source: USS Pueblo Veteran's Association

The crew of the Pueblo were taken ashore, transported to Pyongyang and put in prison.

North Korea's immediate concern was to extract confessions from the crew. They began with Commander Bucher, beating him severely when he refused to admit that the ship had violated territorial waters and that it was a spy ship.

Lt Skip Schumacher recalls the methods they used to finally wear him down.

"They put a gun to his head and said: 'That's it, we're going to kill you.' And they clicked the revolver on an empty chamber, but he still refused," he says.

Finally, when the interrogators threatened to shoot his crew one by one starting with the youngest, Commander Bucher gave in and signed the confession.

Each of the senior crew members was made to sign a similar admission of guilt and these were published as triumphant justification for the capture by the North Korean government.

Back in the United States the news of the Pueblo's capture was greeted with anger and dismay but since there was no intelligence on where the men were being held, a rescue mission was not possible. So the slow process of negotiations began.

Finger of defiance

In Pyongyang the men were being made to write endless confessions of guilt, but they were also busy planning their own acts of defiance - using the North Korean propaganda machine to their own advantage.

On one occasion a group of eight sailors were photographed by the North Koreans to show how well the crew was being treated. In the photograph every sailor held up his middle finger - a lewd gesture that was not recognised by their captors.

"We told them the finger was a Hawaiian good luck sign so they thought that was wonderful," Lt Schumacher remembers.

The photograph was published in Time Magazine, which praised the crew for their courage.

Find Out More Lieutenant Skip Schumacher was interviewed for the BBC World Service programme Witness

Witness airs every weekday, and tells history through the eyes of the people who were there Listen to the programme Browse the archive

When that issue of the magazine made its way to North Korea and when the captors realised they had been made fools of, they reacted with anger and violence.

"They wanted to know all the double entendres and the slang language that we'd used during the 10 months we had been in captivity, and they beat us up very badly," said Lt Schmacher. "It was really quite brutal."

He said it was then that they began to lose hope.

"It finally dawned on us that there was nothing to prevent the North Koreans from sending us to work in the mines or even just taking us out into the parking lot and shooting us," he recalled.

"It was a traumatic experience not knowing your fate."

Free at last

Then just when the crew were at their lowest, they were told they would be released. The negotiations - and a series of US confessions and apologies - had worked.

Pueblo crew Image copyright AP There were 83 crew members on board. 82 of them were freed on 23 Jan 1968. One crew member, Duane Hodges, was killed during the seizing of the Pueblo

The men were freed on 23 December 1968, exactly 11 months after their capture

The captain (shown in photo above) of the ship was nicknamed Pete, a name he choose for himself as a child after seeing a character in a cowboy movie by that name

In 1970 Commander Lloyd M. Bucher told his version of events in the book Bucher: My Story. He died in 2004 Source: USS Pueblo Veteran's Association

But before they left, there was one last act of defiance.

When the North Koreans ordered Commander Bucher to record a thank you message to his captors, he included the word paean which translated as "to praise" in the Korean-English dictionary but sounds like the phrase "to pee on".

Skip Schumacher recalls with humour and pride their final act of resistance as the men walked across the "bridge of no return" at Panmunjom - a village at the border between North and South Korea - to freedom.

"Blasted on the loud speakers for all to hear came the booming voice of Commander Bucher wishing to pee on the North Korean navy and most of all pee on Premier Kim ll-sung!"

Back in the US, Commander Bucher faced a court of enquiry for his surrender to the North Koreans; a court martial was recommended but charges were never pressed.

It was 1989 before the men received medals in recognition of their ordeal.

But there are still some in the US Navy who believe the crew should have fought to the death rather than allow themselves to fall into enemy hands.

Lieutenant Skip Schumacher was interviewed for the BBC World Service programme Witness. You can listen to the programme or browse the archive.