The ship with with 25 crew members became the largest vessel to have been captured in the history of piracy and is a worrying an indication of the crisis facing shipping lines.

“If this menace is not stopped immediately, it will have retrogressive effects on sea trade and may affect prices of basic commodities in the world,” said a maritime official who did not wish to be named.

Somali pirates, who have in the past targeted small vessels, have grown in sophistication, hijacking container ships and now supertankers.

Before the weekend attack, such daring raids were considered to be beyond their capabilities.

Mr Gilbert Langat, the chief executive officer of the Kenya Shippers Council, which represents cargo owners, said the hijacking of the supertanker with 320,000 tons of oil was likely to increase the cost of insurance premiums due to the high risk involved in transporting cargo through the Gulf of Aden.

If the cost of insurance becomes prohibitive or the danger of using the Gulf of Aden becomes too great, shipping companies may avoid the gulf and take the longer route to Europe and North America through the Cape of Good Hope, says Captain Adnan Banafa, the assistant harbour master at Kilindini.

The longer route is the only available alternative for huge ships but it will also increase the time it takes to transport goods by three weeks.

According to Mr Banafa, the extra time spent on the voyage and the increased consumption of fuel by the ships will definitely increase the cost of freight.

One of the largest shipping lines in world, Odfjell, on Monday announced that it would stop using the Gulf of Aden in favour of the safer Cape of Good Hope route.

There is also a potential danger of catastrophe that would make shipping lines to be compelled to avoid the troubled waters off the coast of Somalia. “Large oil tankers pass through the Gulf of Aden and the danger exists that a pirate attack could cause a major oil spill in what is a very important ecosystem,” Mr Banafa said.

And Mr Wilfred Kagimbi, head of the maritime and safety department at the Kenya Maritime Authority, agrees that pirates have become more sophisticated in the last one year.

Whereas in 2007, piracy was only focused on Southern Somalia and Mogadishu port, attacks in 2008 have been taking place in the Gulf of Aden.

“They have graduated and today they use heavy guns and rocket propelled grenades,” Mr Kagimbi said. In his view, the pirates are more determined now than at any other time.

According to Mr Banafa, pirates now use fishing trawlers hijacked from the sea shore and use them as staging posts for further attacks in the ocean. They also operate small skiffs with powerful engines that can be pulled up to the beach. These smaller boats are fast but lack the range necessary to mount a successful attack.

The use of the fishing trawlers, also known as mother ships, increases the pirates range.

Any ship that is over 300 tonnes, says Mr Banafa, is required by maritime regulations to have an Automatic Identification System which helps the vessel to detect and identify any ship in the deep seas and its characteristics. 

When the hijackers use the mother ship, this gadget helps them to find their target. It also helps them locate the naval ships patrolling the waters, making it difficult for the soldiers to stop attacks on ships.