I see where you're coming from - but I have to disagree.
Firstly, dual input gears do exist.
Secondly, two propellers would cause forward thrust outside of the keel line when using electrical or diesel power only, causing drift.
#Two propeller for the boat
main wave
atomic crescent
You could stack them front and back and do a little future-tech thing where the propellers changed their slope to straight to avoid creating drag, if you REALLY wanted to be fancy about it. But it would be an awful lot of asset work for something that was just aesthetic, and most people wouldn't look at.
peak ingot
Gearboxes: exist
wet parcel
That's not how it works.