Prince William is to patrol for drug smugglers in Caribbean seas during a two-month attachment with the Royal Navy, it said Saturday, the AFP reported.
William, the 25-year-old second-in-line to the throne, will begin his naval deployment on Monday.
The prince is an officer in the army but is also training with other parts of the British military, of which he would be commander-in-chief when he becomes king.
His Caribbean attachment will be followed closely by the British media after stories suggesting the prince may have been afforded privileges unavailable to other military personnel.
Last month, the Ministry of Defence confirmed he had landed a Royal Air Force helicopter at his girlfriend Kate Middleton's family home during a training session.
This came days after reports that he flew a military helicopter to a stag party for his cousin Peter Phillips, stopping to pick up brother Prince Harry en route.
William will learn basic skills like navigation and boat handling at first before spending five weeks on HMS Iron Duke, which is stationed in the Caribbean.
The frigate's crew will be involved in operations to catch drug runners which have seen British vessels seize around 20 tonnes of cocaine in the north Atlantic in the last 18 months.
Rear Admiral Robert Cooling, assistant chief of naval staff, said of William's new role: "It will be a real thrill and privilege -- not a pain in the ass -- for the ship's company.
"He's going to come just like any other young officers and do all the things that young officers get involved in."
William will be known as Sub-Lieutenant Wales and will follow his father Prince Charles, uncle Prince Andrew and grandfather Prince Philip, who have all spent time in the navy.
Harry was forced to cut short his deployment with the British army in Afghanistan this year after foreign media broke a carefully arranged news blackout.