Prince William is to go into action fighting the modern-day pirates of the Caribbean. He may be armed if he joins Royal Navy boarding parties that stop cocaine traffickers trying to smuggle drugs in fast launches.

The role is a consolation to the prince after he was banned from going to war in the Gulf with the Royal Navy because of fears his presence could provoke a terrorist attack on British ships.

Instead he will serve on a vessel monitoring the drugs trade in the Caribbean.

The navy said the Iron Duke’s patrol of the north Atlantic and the Caribbean had “a strong programme of operational tasking”, including counter-drugs operations and being on standby for disaster relief during the hurricane season.

“We seized 20 tons of cocaine in recent operations,” said one naval officer. “These guys are not cruising around from island to island. These guys are out there doing the business.”

The prince was “naturally and commendably keen to be as close to the front line as possible”, the Ministry of Defence said, adding that “operational security considerations” had to prevail. At the worst, forces chiefs feared his presence in the Middle East could provoke an attack similar to the Al-Qaeda assault on the USS Cole off Yemen in 2000, which killed 17 American sailors.

The worries about William’s deployment echo those about his younger brother. Prince Harry was banned from joining his regiment — the Blues and Royals — in Iraq in 2007 because it was considered too dangerous.

He later served in Afghanistan in secrecy for 10 weeks until his cover was blown by the Drudge Report, an influential American website, and he was pulled out for fear he might become a magnet for Taliban attacks.

Harry said during his deployment that William was “a bit jealous” and had written to him to say how proud their mother, Diana, Princess of Wales, would have been of him for serving on the front line.

The concerns about William are more acute, given his position as second in line to the throne.

William, 25, also an officer in the Blues and Royals, has already spent time on secondment with the RAF. He will start his naval training tomorrow and will later spend five weeks on the Iron Duke, a Type-23 frigate.

The prince will serve as Sub-lieutenant Wales, the naval equivalent of his army rank of lieutenant. Like his service with the RAF — which ended in controversy when he flew a Chinook helicopter to a stag party and to the family home of his girlfriend Kate Middleton — his time with the navy is designed to prepare him for a future role as monarch and commander-in-chief.

Although he will learn to fly other types of helicopter during his training, William will not be allowed to pilot the Lynx aircraft on board the Iron Duke because of the specialised nature of taking off and landing on a ship.

Commander Mark Newland, the Iron Duke’s commanding officer, said William would have “a primary role planning disaster relief operations”. His other duties will be primarily based around watch-keeping and contributing to the counter-drugs planning.

“What we intend is to show him as much as we can about life on board an operational warship,” said Newland.

Sharing a four-berth cabin, with the toilets or “heads” down a nearby corridor, William will be woken at 6.30am and have breakfast 45 minutes later before starting his duties. These will include work in the operations room and in the weapons and logistics departments. He will also gain experience on the bridge.

Serving with the navy is a family tradition. His grandfather, the Duke of Edinburgh, fought at sea in the second world war and his uncle, the Duke of York, was a helicopter pilot in the Falklands war. The Prince of Wales served for five years in the 1970s and commanded a mine-hunter.

Read Mick Smith's defence blog for Times Online

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