I am using the Pavement Drive Assist Continued mod (https://mods.factorio.com/mod/PavementDriveAssistContinued) to drive around in my vehicle sometimes and it gave me a neat idea - use it as system for waterways instead of current system fake rails and trains.

It should be possible to support it by adding custom water tiles and making all ships a "car" type vehicle. It could be an interesting, new and engaging mechanic to think about ships in that way instead of just another train system. A switch to toggle during world generation that tells cargo ships mod to enable the tilemap navigation system (disabling train waterways and other) or the legacy train system would be useful in that case.