Upstairs in a public house on the English south coast, 18 men are preparing to take on the pirates of the Indian Ocean.

Around antique polished wooden tables scattered with laminated charts, handouts and smartphones, they sit in attentive silence as teachers in jeans and T-shirts discuss pirate tactics and the hazards of the law. Almost to a man, the students - their haircuts short, their arms muscled and tattooed - have military experience: some on well-paid, dangerous private security contracts in Iraq or Afghanistan.

It almost feels as if history is repeating itself. The Blue Boar pub is in a building that dates back to the 18th century, when Poole was one of England's busiest trading ports and ships sailed the globe with cargoes of cotton, silk, tea, cotton, spices and opium. Those privately owned vessels were armed like warships, equipped to fight off pirate attacks and privateers far from naval help. Now, it seems, one ocean at least is becoming lawless again.

Sailing from havens on Somalia's coast, young men with AK-47s, rocket-propelled grenades, grappling hooks and ladders have wreaked havoc with regional shipping over the past six years. Dozens of warships from the world's navies have failed to stem the attacks leading a growing number of shipowners to turn to private security companies. It's a lucrative trade, and there's no shortage of applicants for the three-day "ship security officer" course run by former Royal Marine commandos John Twiss, Nick Williams and their company, Independent Maritime Security Associates (IMSA).

"We're probably training twice as many people as we were last year," 55-year-old Williams told Reuters in the pub's function room, which serves as a classroom. "If you look at the way things are going in the Indian Ocean, it's just getting worse. The work is there, and there are guys who want to do it."

But even these tough, no-nonsense men -- confronted with a wheelchair-bound Reuters correspondent and a flight of stairs, they simply haul wheelchair and reporter aloft and carry them to the first floor -- are far from blase about what they might face.

"The standard operating procedure for the pirates these days is to fire into the superstructure of the vessel to intimidate the master," Williams tells the group. "Some of these attacks now last upwards of 90 minutes. It takes a lot of bottle to hold your nerve during that."

The class would not be so popular if the world's navies had managed to fix the problem. Ships from the European Union, NATO, a separate U.S.-led coalition and newer powers such as South Korea, India, China and Russia have all sailed to the waters off Somalia in recent years. Loosely coordinated through meetings in Bahrain and a secure internet chatroom, they have managed to reduce attacks at choke-points in the Gulf of Aden, between Yemen and Africa. But the pirates have responded by shifting further out into the Indian Ocean, which naval commanders say is too big to police.

Pirate activity has risen steadily. The first three months of 2011 were the worst on record, the EU says, with 77 attacks and hijackings -- up from only 36 in the same period of 2010. The pirates have started using hijacked vessels -- including giant tankers the size of skyscrapers -- as mother ships, so they can operate throughout the stormy monsoon season and far further out to sea than before.

The worsening situation, say experts, has made it almost inevitable that today's merchant ships will buy in their own armed protection. "Nation-states don't appear to have the ability or the enthusiasm to solve the root problem," says Nikolas Gvosdev, professor of national security studies at the U.S. Naval War College in Rhode Island. "That leaves the private sector having to manage effectively on its own."

In a world where power is fragmenting, this raises serious questions. Should shipping lines be allowed to arm their vessels? Does carrying ex-soldiers change the legal status of a merchant ship? Who's policing what companies do to defend themselves? And why are the w