Reported as Ships to Ease Overcrowding for British Prisons.
In his book on the origins of modern Australia, The Fatal Shore: The epic of Australia's founding, Robert Hughes spends some time describing the wretched condition of the ships used as "prison hulks" before the prisoners were loaded onto other ships to be sent to Australia in the late 18th and early 19th centuries. More here.
Their use during the American revolution, well-
More Americans died in British prison ships in New York Harbor than in all the battles of the Revolutionary War.
And, as noted here, there have been more recent uses, as occurred off Palestine in 1947:
In Haifa, British soldiers transferred the Exodus 1947 passengers, exhausted from the sea journey and the battle, to three freighters converted into caged prison ships. Thereby began Operation Oasis.The ships eventually ended up in Germany with the refugees being forced to leave the ships.
The next day, the three caged prison ships, the Ocean Vigour, the Runnymede Park, and the Empire Rival, departed Haifa with the Exodus passengers. 1,464 people were accommodated on the Ocean Vigour, around 1,409 on the Runnymede Park and 1,526 were crammed into the belly of the Empire Rival.
The refugees assumed they, as illegal emigrants, would be interned in camps on the island of Cyprus. What was initially a rumour was later confirmed: the three prison ships were sailing towards the European mainland, back towards France.
The conditions on board these ships were terrible. The refugees lay crammed together in the bare holds of the freighters.
Not a happy history of "prison ships."
Plus ça change, plus c'est la même chose.