Sometimes%2C%20to%20be%20rescued%20you%20have%20to%20be%20heard.%20The%20Storm%20is%20the%20loudest%20whistle%20we%20carry.The%20unique%20patented%20asymmetrical%20shape%20is%20designed%20to%20augment%20and%20amplify%20sound%20like%20no%20other%20whistle.The%20Storm%20even%20works%20underwater%3B%20its%20sound%20can%20be%20heard%20up%20to%2050%20feet%20away!The%20Storm’s%20focused%203150%20Hertz%20frequency%20is%20the%20most%20readily%20heard%20tone%20above%20other%20noises%20in%20the%20environment.A%20whistle%20is%20vital%20for%20signalling%20above%20the%20sound%20of%20surf%20and%20whitewater.Remember%2C%20in%20most%20on-the-water%20situations%20a%20sounding%20device%20like%20a%20whistle%20is%20required%20by%20the%20Coast%20Guard.We%20recommend%20against%20attaching%20the%20whistle%20to%20the%20zipper%20pull%20on%20your%20life%20jacket.%20That%20can%20result%20in%20accidental%20unzipping.%C2%A0Specifications%3ADimensions%3A%203.25%26quot%3BL%20x%201.75%26quot%3BW%20x%200.88%26quot%3BTIncludes%3A%20Split%20RingFeatures%3A%20Operates%20underwater