The connection between forced labour and human trafficking and fisheries, particularly illegal, unregulated and unreported fishing, is vile and highly profitable, and may be found in most parts of the world. A fishing vessel can be a place of abuse more extreme than any other onshore. At sea, it is out of sight for long periods of time, with little or no opportunity for fishers to escape. The working and living conditions on board are often simply described as inhumane. Combating labour exploitation in fisheries raises many complex multijurisdictional challenges, most of which, if not all, could be circumvented if States were serious about addressing this phenomenon. This article examines these challenges and the relevant international legal framework, particularly the 2007 Work in Fishing Convention and the 2014 Protocol to the Forced Labour Convention, against the background of the law of the sea and international human rights law.