What is ‘Traditional'?
For those boaters who tell all that their ‘noise generators' are traditional, I'd like to remind them that canals have been around for over 200 years whereas the internal combustion engine has been around for about half that time.
Quiet
If you want your boat to be ‘traditional' pull it by hand or employ a mule! Both of which are traditional and very quiet. Even the later steam-engine boats are quiet e.g. President (if you ignore the sound of the steam whistle).
I greatly admire the quality of pre-war and early 50's engines and the skill of their designers who produced long-lasting and rugged engines. I do like to see a well maintained Ruston, Bolinder or Gardner but would ask why most of their owners have opted for ‘straight-pipe' exhausts which do little to quieten these large capacity engines.
Improve tranquillity
It does not affect the aesthetic quality of the engine but would greatly improve the tranquillity of the waterways if they were to be fitted with effective silencers.
Using modern technology to improve life and not detract from the underlying style of the machinery should be considered. I have a 1962 BSA Bantam which according to traditionalists must have very square profile cross-ply tyres. Not mine, I have fitted modern motor-bike tyres which improves road holding and improves fuel economy.
These modern tyres do not detract from the fact that it still looks like and is a BSA Bantam. Thus a Ruston with a quality silencer is still a Ruston!