Naval vessels from about 10 nations will soon be patrolling the waters off the Somali coast, trying to prevent pirates from hijacking cargo ships. US ships currently surround one hijacked vessel, believed to be loaded with tanks and other weapons. The original destination of those weapons is in dispute.

The area where most of the hijackings occur is in the Gulf of Aden separating Somalia and Yemen. More than 20 hijackings have been reported so far this year. Ships carrying food aid for Somalia and elsewhere often use the route.

Now, Blackwater, a firm providing thousands of private contractors in Iraq, is offering its services to battle pirates.

Claude Berube is a college professor in the US state of Maryland, who has done extensive research and writing on piracy. He spoke to VOA English to Africa Service reporter Joe De Capua about the use of private contractors in anti-piracy efforts.

"I think it's important to note first that historically this has been done. In fact, several hundred years ago, when piracy was rampant off the coast of Africa, it brought English trade in that region to a standstill. And the East India Company actually employed private convoys to protect their ships from pirates. But I think in this day and age, we've seen a rise in piracy because of a number of factors, not the least of which is we've seen a decrease in the number of regular navy ships. And that's not just the United States. That's the British Royal Navy. That's other countries as well. So, there can be just so many ships operating at so many places at the same time," he says.

It's a matter of quantity, not necessarily quality.

"We have very capable ships, probably the most capable ships in the world and the most capable sailors. But you also have to consider that quantity has a quality all of its own," he says.

Berube says that the length of a ships tour of duty in the Gulf of Aden can vary. "That would depend on what kind of agreements they have locally and with each other. That brings up another issue and that is the issue of rules of engagement. Different countries may have different rules of engagement, for example. Earlier this year, the United Nations did try to account for the situation with UN resolution 1816, which essentially provides cooperating navies with the ability to enter into traditional Somali territorial waters. So we'll see what happens with that," he says.

Cost of the private escort duty may outweigh the risk of sailing unprotected.

Berube says, "That would depend I think on the contracts themselves, but if you are a shipping company, for example, you would have to balance off the cost of providing that extra protection versus the potential loss of revenue… The Times of London recently reported, that because of the ten-fold increase in shipping insurance costs through the Gulf of Aden, we were looking at a potential of at least $160 million a year just in additional insurance rates for companies. That's not inclusive of course of other costs such as delays in shipment. Because if you are going from port A to port B, there is a daily investment and if you lose that investment because a ship has been taken by pirates for say, 45, 60 or 90 days, you have a significant loss to your company. There is the potential for the loss of life."

There are other potential costs as well. He says, "If you look at the average rate according to most media, the ransom has ranged anywhere from a million to two million (US dollars). One paper recently reported that there's one ship in the region now that the ransom was at about $32 million. It's since gone down considerably."

Berube says that his research shows most agree private contractors would provide escort duty and not hunt down pirates. "This is really simply just an extension of security that is already provided on some ships. We have armed riders for example. Some shipping companies are providing people on board to protect themselves from pirates," he says.