'Terrifying ordeal' of a pirate hijacking
23 February 2012 Last updated at 18:01 GMT
Dozens of international warships deployed to the Indian Ocean and the presence of armed guards on commercial vessels has reduced the number of pirate hijackings.
Pirates have responded by becoming more violent and extending the area in which they operate.
The BBC's Will Ross takes a look at the hijacking of a Kenyan vessel, which was released last year after a terrifying ordeal for the crew.