Yes, the Hornet rechargeable electric air horn has no compressed gas so it can be transported safely on an airplane. Traditional disposable compressed gas air horns are prohibited in both carry-on and checked luggage on passenger airplanes. In addition, they cannot be shipped air freight as they are classified as hazardous goods.
In Canada, the Small Vessel Regulations require that all boats carry some form of sound-signalling device, such as a whistle or horn. The requirement depends on your type and size of boat. Approved sound-signalling devices and appliances must be audible for a minimum of 0.93 km. In the USA, for boats up to 65 feet
Below is a list of the common information that is communicated by recreational boaters using an air horn. The signals must be audible for at least one-half mile. Note: A short blast = one second. A prolonged blast = 4–6 seconds. Changing Direction: One short blast tells other boaters, “I intend to pass you on