Rothco 10358 black storm US Navy seals All-Weather safety whistle - navy seals and coast guard approved. Official USN whistle The storm all-weather safety whistle is the loudest whistle in the world Its unique patented design allows it to be heard under water, up to 50 feet. The Storm Whistle creates a clear, high frequency sound, with a power rating over 75% greater than other referee and safety whistles. The Storm Whistle is relied upon by the US armed forces, various US military, police, campers, hunters, sporting events, hikers, scuba divers, and firefighters. Adopted by us military and us navy seals When being heard is a matter of life or death For personal protection. Extremely loud. Made in the USA and GSA compliant.