Dive Alert-Plus v.2 is a specially designed, small, lightweight air horn that uses quick-connect/disconnect hose couplings to become an integrated part of your power inflator, breathable/inflator and buoyancy compensator. Installation is easy and only takes a moment. Dive Alert-Plus does not require any modification of your other equipment, and it does not interfere with the normal operation of your other equipment. Dive Alert-Plus enables divers to signal both above and below the water's surface.There are three different models available; one for approximately 85% of standard power inflator mechanisms model DV1. There are several breathable/inflator mechanisms that require a larger coupling for a higher flow of air so there are two models to accommodate them. The model DV2 and the model DV3 (see list below).Why have Dive Alert Plus? What would you do in a diving emergency if you needed to get the attention of the pick-up boat or someone else on the water's surface? Before Dive Alert-Plus Scuba divers had relied on whistles or a SMB (surface marker buoy) as their only signaling devices in such an emergency. But if the diver is disabled and can't blow into a whistle (or deploy the SMB) the whistle makes no sound at all. Or if the boat operator is not looking in the direction of a diver with a SMB deployed (if the diver was able to even deploy the SMB) the diver goes un-noticed.Or, what would you do if you wanted the attention of your dive buddy underwat