The pirates counted the cash after it arrived by parachute drop and then began leaving the Ukrainian arms ship in small batches, navigating the choppy seas in small skiffs, pirate Aden Abdi Omar told The Associated Press after arriving in the central Somali town of Harardhere.
American sailors from two nearby warships inspected the departing boats to ensure that the pirates didn't take any weapons from the MV Faina's cargo, according to a spokesman for the ship's owner, Mikhail Voitenko.
But the U.S. Navy did not take action against the pirates because they still hold eight other ships and crew, said Cmdr. Jane Campbell, a spokeswoman for the U.S. Navy's Bahrain-based 5th Fleet.
"Even when you release Faina, there are still 147 mariners held hostage," Campbell told the AP on Thursday. "We're concerned for their well-being."
The $3.2 million was among the largest-ever reported ransoms.
Later Thursday, Faina's captain Viktor Nikolsky said his ship was under the protection of the U.S. Navy and will head to Mombasa, Kenya. He also said all crew members needed medical attention.
Ships from the U.S. Navy's 5th Fleet have closely monitored the Faina and its 20 surviving crew throughout the standoff after the captain died of a heart attack, and the U.S. sent medical workers to the ship after the pirates left.
"We are extremely pleased" at the release, said Vice Adm. Bill Gortney of U.S. Naval Forces Central Command. "The United States Navy and our coalition partners will continue to fight piracy, and work with the international community to find a long-term, shore-based solution to this maritime crime."
War-ravaged Somalia has not had a functioning government for 18 years and pirates made up to $80 million hijacking ships for ransom last year, seizing 42 vessels off the country's 1,900-mile (3,000-kilometer) coastline along the Horn of Africa.
The Sept. 25th seizure of the Faina and its cargo of weapons was a wake-up call about the danger that piracy posed to one of the world's most important trade routes, said London-based analyst Roger Middleton.
"It showed Somali piracy no longer affected just small coastal vessels but important and dangerous cargos," he said.
In November, pirates hijacked the Sirius Star, a Saudi supertanker filled with crude oil. And last week they took the MV Longchamp, a German tanker filled with explosive gas.
Intelligence agents had feared the weapons onboard the Ukrainian ship - which include 33 Soviet-designed tanks and crates of small arms - could fall into the hands of Somali insurgents who the U.S. State Department says have links to al Qaeda.
Diplomats in the region previously have said the cargo was destined for southern Sudan, something the autonomous region has denied. Kenyan government spokesman Alfred Mutua repeated Kenya's claim to the cargo Thursday.
The Somali pirates have netted between $50 million and $80 million in the past year, according to Middleton.
The high ransom payments mean pirates are unlikely to stop attacking. But now warships from countries including India, Britain, France, Germany, Iran and the United States are patrolling the waters off Somalia. China and South Korea also have ordered warships sent to the region.
Middleton said the naval interventions had reduced the success rate of attacks to about 20 percent. Last year, pirates took 42 of the 111 ships they attacked.
Graeme Gibbon Brooks, managing director of the British company Dryad Maritime Intelligence Service Ltd., said a recent drop in attacks was partly attributable to coalition activity and partly to unseasonably bad weather.
Most of the 16 attempted hijackings in 2009 occurred in the first two weeks of January, when the weather was fine. Three ships have been captured by pirates off Somalia this year.
But pirates are showing a worrying new sophistication in their attacks, several experts told the AP, including greater use of global positioning systems that allowed them to extend their range. Automatic identification systems - originally designed to stop ships from colliding - can also identify potential prey from a radio signal they put out.
A recent article in Jane's Intelligence Review says the pirates may be trying to buy magnetic mines and heat-seeking missiles that can be fired from the sea. Brooks said pirates also were jamming emergency frequencies with Arabic music or sending out false distress calls to lure warships in the wrong direction.
Pirates also have begun to mount diversionary assaults or multiple, simultaneous attacks on several vessels.
"We've gone from a pattern of sporadic attacks to a situation where the pirates coordinate," he said.
In one incident last week, pirates simultaneously attacked three ships. Coalition forces were able to save two, but the third - the Longchamp - was captured.
Vice Admiral Gerard Valin, the commander of a French naval task force, said there are five broad pirate gangs operating from Somalia, each with about 200 to 500 members.
In a typical attack, up to two dozen armed pirates in motorized skiffs draw up alongside ships, sometimes firing at the bridge, and use grappling hooks and rope ladders to clamber aboard. Many ships have no more than two dozen crew members anyway, usually without armed protection.
The coalition does not issue exact figures for security reasons, but Middleton said there are between 20 and 30 warships off the Somali coast. But Valin said even with all the extra firepower, it was hard to prevent attacks, due to the vast waters and the pirates' increasing ingenuity.
"I will not say congratulations," Valin said. "But we have to respect the adversary."