Thank you very much!
About the engine sound. I understand why this is useful. But in this game, the sound is (at least I try to) located in 3D space as well. That means that the engine is barely hearable at the bow. Similar to (at least some) real narrowboats.
Anway, I am aware that this all is not perfect so I plan to have a closer look at the audio in the future. (Things like sound degradation with distance. Tunnel sounds etc..)
Michael