ALARM DEVICE

PURPOSE:To directly and immediately recognize a dangerous hydraulic pressure state by attaching a hydraulic pressure sensor for sensing prescribed hydraulic pressure to a snorkel, etc., of a diver, and transmitting an alarm signal, based on its information signal. CONSTITUTION:A snorkel 1 is constituted of a mouthpiece 3 attached to the lower part of a cylindrical snorkel body 2, and an alarm device 4 provided on a drain part of the lower end part 2a of the body 2. In this state, when a diver dives to prescribed water depth and reaches a dangerous hydraulic pressure area, since the lower face of a protective sheet 13 in the alarm device 4 is pressed to the inside by hydraulic pressure, conductive rubber 16 is compressed through a first electrode 14. As a result, the current quantity (i) flowing between a first and second electrodes 14, 15 is varied, a sound source circuit operates and an alarm electronic sound and an electronic voice are transmitted from a loudspeaker 8. Accordingly, the diver recognizes directly and immediately this alarm sound and can quickly take a danger avoiding action, etc.