If you have a lot of interactions with canal boaters, it might be interesting to create one or more custom layers in mapcomplete. Give MapComplete Studio a shot (but keep in mind that it is not exactly user friendly, let me know where you get stuck and I'll try to fix it).
If you have created one or a few layers you like, let me know and I might include them in the production version of MapComplete.
Would you mind on elaborating how you would expect it to work?