If there's ANY water big enough to put a boat in anywhere near you, then there's a market for the flaregun. Coast Guard reg.s require safety devices, ie. flotation devices (wearable and throwable), signaling devices (flares and radios), and proper lights (port, starboard, stern, and at anchor lights) to name a few. Requirements depend on the size of the boat and/or the number of passengers/crew. My 23 ft. sailboat (sailed in the Illinois river) is required to have life jackets for all passengers, at least one throwable PFD, a VHF radio, and yes, flares and a launcher, ie. gun.
Sometimes, the law DOES make sense.

Troy