My only experience with a boat horn is with one of those little handheld air horns which we carried in our 16' Skagit and never used. Now I'm in the process of restoring a 22' C-Dory and am trying to decide if I want a fog/hailer speaker or horn or both. I've purchased an ICOM IC-510BB VHF that has a hailer/fog horn feature that requires an external "hailer horn speaker", and is operated from the microphone. My understanding is that this allows you to talk over the speaker or send a fog horn sound over the speaker. The ICOM speaker is 40 watts. I know I can also buy a separate trumpet style air horn that would be operated by a button at the helm. Would love to hear folks' thoughts on the benfits of one over the other or both. I'll be operating in the PNW where fog is common. Thank you!