Generally true except on the river system. The tow will respond if they feel you are a concern. The difference being they do it over the radio with the shorthand of on the 1 or on the 2, often with a difficult to understand gravelly southern accent (which Tammy loves). If you have a female on board, it is often handy to have her make the call. For some reason, I can call multiple times and get no response but Tammy gets on the mic and suddently it's, "sure darlin,..."   On the other hand, imagin the situation after a major event like fireworks. You have hundreds of boats milling about crossing paths in close proximity. If they all followed the letter of the law, you would need a crew member just to run the horn.   The only place passing is really bad is in narrow channels especially near junctions where they don't know which way you are going to turn and you can't simply turn away and ride out their wake. On a wide open body like Lake Huron, I would be more annoyed you choose to wake me by coming so close as to need to signal (assuming it's not entering a harbor).   So now some questions: So do you collect drift wood for fuel? Do you have a steam powered generator? Can you draw hot water off the boiler?   Lots of chart software and gps integrated autopilots, nothing special as far as I can tell with a steam powered vessel.   Mike & Tammy Valhalla II   Snip: Passing whistle signels are rerely given, and more rarely responded to. 3 years ago on Lake Huron?I was overtaking a steam launch on her port side and gave a single short blast, and was answered by a single steam whistle blast as was proper.