A prison ship is a seafaring vessel used to transport or house convicts, enemies of the state, or political dissidents. Typically commissioned by countries at war in foreign lands, these ships were a convenient way to restrain undesirable people without the expense of having to establish a permanent facility on land. Prison ships were often repurposed vessels that were previously used by the country’s navy.
Historically, prison ships were popular with Great Britain during the American War for Independence as holding facilities for captured rebel soldiers. Britain also used prison ships to transport convicts to penal colonies located on other continents. The Nazis used floating prisons to hold Jews for transport to concentration camps during World War II, and the Russians used ships called death barges to imprison political dissidents during the Russian Civil War.
The use of a prison ship was often the solution to the problem of what to do with captured enemies while in uncontrolled territory or during times of widespread instability. Prisoners were not sent to floating accommodations with the guarantee of eventual release, good treatment pending trial, or even basic humane living conditions. Many prisoners died of deplorable conditions or were slaughtered by one side or another in the conflict.
This type of imprisonment fell out of favor over the centuries as international standards for basic human rights and the treatment of prisoners during times of war were established. Some jurisdictions, however, will still use a prison ship as an official facility in its penal system. In this sort of circumstance, the ship used is specifically design to humanely house prisoners rather than simply being a repurposed military vessel.
Although it is commonly believed that the horrors of the use of ships to imprison and torture enemies extra-jurisdictionally, on the unaccountable expanse of the high seas, and without the benefit of legal procedure to protect basic human rights is a historical anomaly, the U.S. has been accused by human rights groups of using the practice to hold and transport enemy combatants in the War on Terror. As in wars of the past, a prison ship seems to be the easiest way for the military to handle prisoners while in foreign territory. The U.S. government has denied using ships as floating prisons in the historically notorious sense, however, and it has been proven that prisoners were at least transported by ship to locations outside of their home country.