WASHINGTON (CNN) -- Colin Darch was piloting his slow-moving tugboat out of the Red Sea close to Somalia when heavily armed pirates sped up next to him screaming and firing weapons.
Colin Darch and his crew were taken hostage by pirates earlier this year and held for six weeks.
He spun his boat, the giant tug Svitzer Korsakov, with its powerful thrusters to create a wall of water in an attempt to swamp the pirates' speedboat. One pirate was knocked overboard from the rushing water and the boat's boarding ladder was swept into the sea.
"I had a good feeling that we would get rid of them, but my heart sank when I saw the second boat speeding toward us," Darch told CNN recently.
He knew that with boats on each flank and almost 20 pirates armed with AK-47s, he and his five crew members would not escape. The pirates rushed aboard, firing their weapons into the air and ordering the crew to lie down.
It was the beginning of six weeks in captivity. "We were told that if we behaved no one would get hurt, but if we did something wrong, we would be shot," Darch said. See how the U.S. Navy responds to pirate takeovers »
The pirates took them up and down the eastern coast of Somalia, anchoring at various spots along the way. They sometimes brought live goats aboard and slaughtered them for food.
"They made it clear we were being hijacked for ransom and kept in constant contact with the owners in Copenhagen [Denmark] all the time negotiating with the company," Darch said.
Authorities say such hijackings are are on the rise. Gangs of heavily armed Somali pirates with years of fighting experience roam hundreds of miles of unsecured waters off the coastline hunting commercial ships for money and goods.
The pirates will often hold a ship and its crew for weeks or months waiting for a ransom to be paid by the ship owners.
"We have seen piracy from Somalia increase over the last five years because the militias have discovered this is a good source of income," said Pottengal Mukundan, director of the International Maritime Bureau, which monitors piracy around the world.
In the case of the Svitzer, a reported $700,000 ransom was paid for the crew's release, although Darch and the Svitzer company would not confirm the amount for security reasons. In another recent incident, pirates released a Spanish fishing boat off the Somalia coast, only after they received a reported $1.2 million in ransom.
According to the International Maritime Bureau, the number of ship hijackings and attacks off of Somalia has risen dramatically over the last five years, with a high of 31 known attacks in 2007. Attacks this year are already up over 20 percent from last year, including the high-profile hijacking of the French luxury ship Le Ponant. Watch helicopter gunships stop pirates from getting away »
Officials also say many pirate attacks are believed to go unreported.
Organizations like the International Maritime Bureau and the Seafarers Assistance Program work with the U.S. Navy to combat and protect mariners from piracy in the region. The Navy has been patrolling the waters off the east coast of central Africa since the September 11, 2001, terrorist attacks in search of al Qaeda militants in the region.
"Until there is an established stable government in Somalia that can enforce maritime law, the risk of piracy in this region will continue," said Lydia Robertson, spokeswoman for the U.S. Navy's Fifth Fleet based in Bahrain.
The Navy works with France, the Netherlands, Britain and Pakistan in what is known as Combined Task Force 150, a maritime coalition that has taken on additional anti-piracy roles around Somalia. The U.S. Navy keeps at least one warship off the coast of Somalia, Navy officials said.
Authorities recommend mariners stay at least 200 to 300 miles from the Somali coast to keep out of range of attacking bandits.
U.S. ships often keep a presence near a hijacked ship and radio the pirates to check on the crew or demand they give up, as was the case with Darch's ship.
"The U.S. called our ship several times a day asking me how we were doing or negotiating with the pirates," Darch said. "On several occasions the pirates became angry with the U.S. demands and turned the radio off; other times I saw Omar [the pirate leader] laughing when talking with them."
Darch said he and his crew -- an Irish engineer and four Russian crew mates -- slowly got to know the pirates during their time in captivity. He said it was clear the pirates "would not be able to harm us as they got to know us."
"As we would talk with them, we came to sympathize with the problems the Somalis faced on land with no effective government, resources or schools. But all the time, we were aware of the Stockholm Syndrome and made sure we did not fall into that trap," Darch said, referring to a condition in which a captive shows signs of loyalty to their hostage-takers.
Darch and his crew were let go on March 18 after the ransom was paid. In all, they spent 47 days in captivity.
"When the money was delivered the pirates divided it among themselves and then we sailed up the coast dropping them off at different ports before they let us go," he said.
The pirates who snatched them were "full of bluster and told lies to make themselves look tougher than they were."
"They were unsophisticated hoodlums, but you never knew if one of them would follow through with their threats," Darch said.
The USS Carney, one of the U.S. ships shadowing the Svitzer, sent a team to look after Darch and his crew, feeding them and giving them medical check-ups before sending them off to a safe port in Oman. From there, Darch was soon reunited with his wife in nearby Dubai.
"As my wife and I sat on the beach in Dubai, I told her I have just done my last job," said Darch, a mariner for more than half a century.
What's his advice to other sailors who come under a pirate attack?
"Stay calm, act as if you don't have any power and that the decisions are up to the owners of the boats. I would also suggest getting to know your captors. The more you get to know each other, it seems it would be harder for them to harm you." E-mail to a friend