Dark Reef

Dark Reef is an underwater prison that houses the worst of the sea's denizens. Murderous Slithereen, treacherous Deep Ones, and sociopathic Meranths are kept in the prison. The interior of the prison is described as a dim labyrinth, patrolled by eels and and guarded by giant anemones. Only the toughest prisoners survive. Slark was once an inmate in Dark Reef, for undisclosed crimes. The Dark Ones may be somehow related to Dark Reef.

Escapes
The Dark Reef Dozen once tried to escape, but failed. However, Slark was able to take advantage of their escape attempt as a distraction to escape himself. To this day, Slark is the only prisoner ever to escape from Dark Reef.

Rising
According to Slark, the Dark Reef will once day "rise", although what exactly this means is unknown.