Abstract: The present invention is directed to a passive ascent rate monitor that is operable to determine a diver's rate of ascent and generate a signal indicative of the determined ascent rate. In one embodiment, the ascent rate monitor outputs graduated audible signals that correspond to a plurality of ascent rate ranges. In another embodiment, the ascent rate monitor generates private audible ascent rate signals allowing a diver to determine their own ascent rate without necessarily outputting signals that may be heard by and/or interfere with their dive partners.