What is the correct fuse for my Depthtrax? NMP Support Center July 02, 2019 13:05 Updated Follow The fuse used in the depth finder is a .25A, 250V fuse. Related articles My In-Dash Depth Finder Won't Turn On My P23 transducer looks like it will move with the boat running. Depth Finder Alarms I glued the transducer in hull and all I get is "---" readings on my display. Glue-In Transducer Instructions with Illustrations Comments 0 comments Please sign in to leave a comment.