By Mark Doyle
BBC World Affairs Correspondent
An increase in piracy off the Indian Ocean coast of Somalia has made these waters the most dangerous for pirate activities in the world.
This luxury cruise liner was attacked by pirates two months ago
Shipping companies say the area has overtaken those traditionally plagued by piracy such as the Straits of Malacca in south east Asia.
The pirates generally use speedboats to steal trading goods or food aid - sometimes impounding ships and crew at gunpoint and then demanding ransoms before they are released.
Somali clan leaders have just signed an agreement to try to end over two decades of factional fighting in the country - and they say they have also made attempts to address the piracy problem.
But the high level of lawlessness off the long eastern Somali coastline reflects the level of chaos there has been on the ground in the country for more than a generation.
The problem does not affect the northern coast of the self-proclaimed and more stable Somaliland as much.
Shipping companies grouped under the International Maritime Bureau (a branch of the International Chamber of Commerce) say there have been 35 incidents of piracy off the Indian Ocean coast of Somalia in the past nine months.
One attack which made international headlines late last year was against a luxury cruise liner. It was foiled when the crew scared the pirates off with an ear-splitting acoustic device developed as a "non-lethal" crowd control weapon.
Many other attacks, particularly against smaller traders or fishermen, do not go reported.
But the weekly Piracy Report of the Maritime Bureau has regular updates.
This week it noted three suspicious speedboats off the Somali coast which followed a tanker. On this occasion there was no reported attack.
Captain Jayand Abhyankar of the Maritime Bureau told the BBC News website: "Somalia's the most dangerous place these days. The Malacca Straights used to be one of the worst, and the waters off Nigeria and Iraq are currently bad. But Somalia's the worst."
The Bureau advises sailors who don't have to visit Somali ports to stay at least 200 nautical miles away from the coast. This is an advisory figure which has been increasing, from first 50, then 100 nautical miles in the past few months.
The Bureau warns: "Heavily armed pirates are now attacking ships further away from the coast."
The fractious authorities in Somalia, keen to be seen to be doing something about piracy, signed a $50m contract late last year with a private company based in the United States which said it would begin coastal patrols.
The government is seeking to end lawlessness on land and on sea
When the contract was announced, some Somalis wondered how it would be paid for, since the authorities are severely short of resources. Somali government officials said "foreign friends" would finance the deal.
The Somali minister for Planning and International Cooperation, Abdi Rizak, told the BBC News website the contract was "in the mobilisation phase".
The minister said it would take time to move resources and equipment to Somalia.
Somali businessmen and international shippers said the only thing which has stopped piracy in the past is when western navies patrol the area.
"What we know is that when western navies patrol these waters, the pirates stay away," said Pottengal Mukundan, Director of the International Maritime Bureau.
The United States sometimes has ships in the region, mainly aimed at monitoring the movements of what it says are suspected al-Qaeda-related groups.
And the Italian government, Somalia's former colonial power, also mounts some patrols.
But the problem will clearly not be resolved in the long term until there is more political stability in Somalia - and more economic development to discourage people from turning to piracy to make a living.