The Lonely Island (yes, really) is a two-masted brigantine with an oily hull and dark, eerie sails. It was owned by pirates who traded in Sleepers and Sleeper body parts; several Sleepers have died and been cannibalized on this boat. Necromancers and similar will be able to detect that significant violent death has occurred here.

Relatedly: the ship is manned by twelve undead pirates, each killed tidily with their hearts stopped by necromancy.

The ship's interior is sparse but spooky, with bone-themed decoration. The bones can manifest into another two dozen skeletons as needed. There are no physical remains of cannibalized Sleepers; all the undead are fashioned out of the slaver crew.

It does not actually have a skull-and-crossbones flag, which is a damn shame, because he would have loved the aesthetic.