Enslaved on a Thai fishing vessel for 11 years, Tun Lin saw his fellow workers lose their minds one after another, with one fisherman jumping into the sea to end his life.

Some would start murmuring or laughing to themselves as they worked day and night in Indonesian waters on the cramped boat, often surviving on fish they caught and drinking water leaking from an onboard freezer.

"It was like a floating prison — actually, worse than prison," the fisherman, who was sold into slavery from Myanmar, said in Samut Sakhon, a Thai fishing hub 40 km (25 miles) southwest of the capital, Bangkok.