a highly sensitive depth finder in which the readings are noted by stylus traces on moving tape, often used by fisherman to locate schools of fish.
An electronic depth sounder that records bottom structure data on paper.
A chart recorder is an electromechanical device that records an electrical or mechanical input trend onto a piece of paper (the chart). Chart recorders may record several inputs using different color pens and may record onto strip charts or circular charts. Chart recorders may be entirely mechanical with clockwork mechanisms or electro-mechanical with an electrical clockwork mechanism for driving the chart (with mechanical or pressure inputs) or entirely electronic with no mechanical components at all (a virtual chart recorder).