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.

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.

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.

"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.

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.