the classic surface signalling device. The most effective and convenient surface signaling device available. DiveAlert is a specially designed, small, light weight air horn that uses quick. Connect / disconnect hose couplings to become an integrated part of your power inflator and buoyancy compensator. Installation is easy and only takes a moment. DiveAlert uses a small amount of air from your SCUBA tank to make a piercingly loud sound. People have been able to hear a DiveAlert one mile away from a diver in need. In conditions where visibility is limited, a DiveAlert can be a life saver. النوع الغوص الحر والغطس