Abyss Torch

Take it on a dive. Its own description calls it waterproof, and that is the whole point: a normal torch goes out the moment you sink, while this one keeps lighting the water around you. On land it does the same job as the plain one, swing included.

Picture a night run to an underwater lab or the crates lying on the seabed. You go down with a diving mask for clear vision and a diving tank for air, and the deeper you go the darker it gets. Without a light you feel your way along walls and swim past the loot. With this in hand you see the crates, and usually the shark before it sees you.

The cost matches the ordinary torch because it is a skin of it: you craft a plain torch from some wood, one cloth and one low grade fuel, no workbench, and pick the Abyss look if you own the skin. There is no blueprint of its own to research.