The invention concerns a mechanical or electromechanical dive watch including hour (4) and minute (6) hands, a pressure sensor (42), a depth indicator hand (14) and a depth variation indicator hand (22), the depth indicator hand (14) providing a diver with an indication of the instantaneous value of the depth at which he is situated when diving, the depth variation indicator hand (22) being at that moment locked at zero, the depth indicator hand (14) being locked in turn when the diver reaches a required decompression stop and the depth variation indicator hand (22) being released to indicate to the diver any variations in his depth relative to the decompression stop depth, the depth variation indicator hand (22) then being returned to zero and locked while the depth indicator hand (14) is released and again indicates the exact dive depth when the diver resumes his ascent towards the surface.