To the Waterline is an off-screen companion adventure in Pillars of Eternity.
In-game description
The pitch:
A Rauatai merchant ship was sunk by Aedyran pirates off the eastern coast of Readceras. Before the ship collapsed into the waves, the pirates made off with a variety of precious treasures, many of which were experimental animancy implements or nautical devices intended for Defiance Bay and Spirento.
The concerned would-be recipients of the cargo are discretely inquiring about potential help. Their hope is to recover the shipments before the pirates learn the value of what they've taken.
The conclusion:
After traveling north from Godhammer Citadel, [Companion Name] arrived in the Readceran port city of Benhaldt. Several of the pirates had landed there and sold much of their stolen booty.
Tips and rumors from merchants and criminal elements led [Companion Name] to the Bone Isles, a small archipelago northwest of Readceras. The more foolhardy pirates put up a fight, but most of them fled with small scraps of cargo.
In the end, [Companion Name] managed to recover over half of what was stolen. One item, a small, curious diving bell, went unclaimed by the conglomerate of merchants that had paid for the recovery.