From Pathfinder Lost Omens Hellfire Dispatches, which isn't enabled.

Stealthy As An Octopus

FEAT 6

Prerequisites Undersea Privateer Dedication; expert in Stealth

You're an expert at using the dark of the ocean to conceal yourself. As long as you're separated from a creature by 20 or more feet of water, the turbulence of the water grants you enough cover to attempt to Hide from that creature.

Pathfinder Lost Omens Hellfire DispatchesORC