Sea piracy is costing billions of pounds and ruining lives, with captors increasingly turning to torture and death threats, seafaring charities have said.
There are around 300 ships' crew members being held hostage by Somali pirates, the charities added.
Over the last eight years, an estimated 4,000 seafarers have been attacked by pirates or been victims of armed robbers while at work abroad.
The figures came as a new programme was set up in London to help seafarers and families cope with the physical and mental trauma caused by torture and abuse at the hands of pirates.
The new Maritime Piracy Humanitarian Response Programme (MPHRP) is intended to help those seafarers and their families cope with the resulting pain and anguish.
It is being funded by the International Transport Workers' Federation's Seafarers' Trust charity and philanthropic group the TK Foundation.
The establishment of the programme comes as investigations continue into the kidnapping in Kenya of British woman Judith Tebbutt, 56, in an incident in which her husband, David, 58, was killed.
The two charities also released testimony from piracy victims. This included a ship's captain held for 71 days by 12 hijackers who was "threatened with a gun to my head" by pirates who were "constantly using drugs", and a ship's engineer who was hijacked for about six months by a pirate group who "sometimes used to torture us".
Another engineer had plastic cables tied to his genitals after being attacked by Somali pirates who also stripped naked and tied up the ship's master and chief engineer and put them in the low-temperature meat-storage room.
MPHRP manager Roy Paul said: "Most people still don't understand that the face of piracy today is very different to the romance of the Pirates Of The Caribbean. Today seafarers are meeting pirates who are really sea terrorists: hard, desperate and violent criminals."