Established in 4693 AR, the Black Whale is a prison on the western part of the Flotsam Graveyard intended for the most notorious or politically sensitive prisoners too dangerous to be kept in the Brine in Puddles.
The prison consists of six beached ships, bolted to it with long chains and each lashed together. The guards and other staff stay on the northernmost of the ships, which holds their quarters, all the rowboats, the armory, and the storerooms. An adjacent ship is home to the galley and processing rooms where prisoners are fed and readied for the other ships. A series of pulleys connects ropes and anchors to all six ships, and during rough seas, the prisoners push a pulley axle on each ship to tow supply ships in.
Due to the nature of these criminals, only the Grand Council holds a complete list of who resides within the prison, and few survive long in the squalid conditions aboard (although death typically occurs only due to natural causes). The Lord Warden of the Black Whale is the Fourth Lord of Laws, Guirden of House Gyr. Due to the importance of these prisoners guards are ever watchful of prisoners breaking out, or outsiders breaking in.
The security of the prison is impressive to say the least. Most obviously, the area sits under the watchful eyes of Fort Tempest (and its formidable siege weapons) and the prison has no shipwrecks near it to aid in any escape. Furthermore, food scraps from the prison and Pilot House are dumped around the razor-sharp reef, ensuring that sharks and rays are always in the area seeking food. Finally, gillmen have recently been hired to patrol the area under the ship to ensure no escapees make it to shore, at the request of the Lord Warden.