Dead Reckon Rangefinding Monocle

Dead Reckon Rangefinding Monocle is a sealed optical monocle that measures distance, relative motion, and angle while leaving one eye free for ladders, hand signals, and incoming trouble. It must be zeroed to the wearer and helmet; loaners produce small errors that become large ones across a docking span. Every sighted object enters a rolling cache, so the monocle can quietly become a record of who stood where when negotiations failed. The interface keeps working after its map, clock, or network feed disappears, using local estimates and prominently marking every guess. Managers dislike the uncertainty flags; crews dislike managers who ask for them removed.