Other crossword clues for answer "PERISCOPE"PERISCOPESub apparatusSubmarine's viewing instrumentSherman tank deviceSub needTubular submarine deviceSub viewerOptical instrument used in trenches.Nautilus adjunct.Optical instrument with mirrors.Optical instrument at sea.Submarine instrument.Seagoing eyeView-finder for RickoverViewer on the NautilusView enhancer