This is a depth gauge that was on board M /S Skogøy, which went on a route between Narvik and Svolvær.
This is a depth gauge from M/S Skogøy which ran on a route between Narvik and Svolvær. It is part of Narvik Museums collection.
To measure the depth, an ampoule was broken and placed in the sleeve.
This was lowered to the bottom.
The ampoule was then read against the measuring rod to find the depth.