More sophisticated pirates are usually members of organized gangs that may commandeer ships and hold crews for ransom.
In some cases, pirates have forced the crew off a ship and sailed it to a port, where they repaint the vessel and give it a new identity through false papers.
Another type of attack involves a coordinated effort by several boats that target a single ship.
"One boat may attack from the front," Mukundun said. "While the bridge is busy trying to avoid a crash, two other boats can sneak up from behind and board the ship."
According to IMB, the waters around Indonesia continue to be the world's most dangerous, with 19 pirate attacks in the first three months of this year.
These waters are among the most heavily trafficked in the world, and organized crime gangs hold sway over parts of them.
"Indonesia represents 25 to 30 percent of the attacks," Mukundun said.
Many attacks occur while ships slow their speeds to navigate narrow straits, such as the Strait of Malacca, a narrow stretch of water between western Malaysia and the Indonesian island of Sumatra (map of Indonesia).
Slowing down makes the ships vulnerable to being overtaken and boarded by armed men traveling in smaller motorboats.
Until recently, none of this year's attacks had occurred in the Strait of Malacca.
But within the last week three ships were attacked in the area, two of them ships carrying United Nations food aid to Acehan Indonesian city still suffering the ill effects of the December 2004 tsunami.
Now a crackdown on piracy by the Indonesian authorities appears to be paying off. The Indonesian navy has so far arrested numerous pirate gangs in several intelligence-led actions.
"It still remains to be seen if the situation in the Strait of Malacca has been improved in the long-term," Mukundun said.
Pirates of Somalia
If the situation has improved somewhat in Indonesia, it has gotten far worse in the waters off Somalia (Somalia facts, maps, more).
The country, which sits on the East African coast, has seen attacks shoot up from 1 in 2004 to 19 in 2005.
In June last year a ship named Semlow was transporting rice to northeastern Somalia for the UN World Food Program the New York Times reported.
Heavily armed pirates attacked the boat in the middle of the night. The ten-man crew was held hostage for 101 days before being released in October.
"These pirates are worse than the pirates we read about in history books," one of the captured crew members, Juma Muita, told the newspaper.
"These Somali pirates are better armed, and they want ransom, not just our goods."
In another Somalia incident, pirates lured a vessel close to shore by setting off distress flares.
And late last year a luxury cruise liner with some 300 tourists came under attack by Somalian gunmen in speedboats.
The pirates fired automatic weapons and rocket-propelled grenades at the cruise ship but were unable to board.
In most cases prosecuting pirates is particularly difficult, because many of the attacks take place outside the territorial waters of any state.
But attacks off Somalia are likely increasing because more pirates are taking advantage of the lack of a functioning government in the African country.
"There's a law-enforcement vacuum in Somalia into which pirates and other criminals have moved in," IMB's Mukundun said.
What's more, some of the private groups professing to fight piracy are instead reportedly engaged in it.
One such group, calling itself the National Volunteer Guard, intercepts small boats and fishing vessels in southern Somalia.
A similar group operating around the capital city of Muqdisho (Mogadishu) is known as the Somali Marines.
The problem has become so bad that IMB sends out daily signals to ships to steer at least 200 miles (322 kilometers) clear of the Somalian coast.
Mukundun says pirates usually seek to take boats within 12 miles (19 kilometers) of the Somalian coast, because the criminals know no rescue vessel from another country can legally follow beyond this border.
The U.S. Navy, however, recently started patrolling the international waters off Somalia as part of its broader antiterrorism activities in the region, according to the New York Times.
In January the U.S. destroyer Winston S. Churchill intercepted an Indian vessel far off the Somalian coast. The vessel had been secretly taken over by pirates some days before and was being used as a base for pirate attacks.
The pirates were taken into custody and transferred to Kenya, where they face trial.
Their lawyer reportedly maintains that his clients are just fishers who became stranded at sea and sought the aid of the Indian vessel.
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