By Nick Childs
BBC world affairs correspondent
Piracy attacks on shipping have increased by 14% in the first three quarters of this year, a report by the International Maritime Bureau says.
Pirates use "mother vessels" to launch smaller boats well out to sea
The increase is in large part because of a jump in incidents off the west and east coasts of Africa - with Somalia again a key source of concern.
The IMB attributes this to the December ousting of Islamists from Somalia.
IMB Director Pottengal Mukundan says the pirates in Somalia are now operating with impunity.
The Union of Islamic Courts cracked down on piracy while it held sway in the capital, Mogadishu, and much of the south of the country, last year.
There is currently a petition from the UN body, the International Maritime Organization, for the UN Security Council to ask the Somali government to take action against the pirates, including possibly letting foreign naval vessels enter Somali territorial waters.
The IMB advises merchant ships to stay at least 200 nautical miles from the Somali coast.
The UK-based global watchdog, which comes under the auspices of the International Chamber of Commerce, says the pirates appear to be using "mother vessels" to launch smaller boats well out to sea.
The bureau is worried as the downward trend in piracy over the last few years looks to be at an end.
Overall, Mr Mukundan says the level of pirate attacks in high-risk areas remains unacceptable.
In all, there have been 198 incidents in the first nine months of this year, compared to 174 in the same period last year.
A total of 15 vessels have actually been hijacked this year so far.
Despite the latest upswing, though, overall attacks are still fewer than they have been in recent years, except for 2006.