Besides going off topic some it seems to me that most people from either side want it to be separate.
Engine/Motor Definitions and Classifications
1. Displacement
The cubic inch displacement of a power plant shall be the sum total of the displacement
of all cylinders in the power plant. The...
The way the Impba rules read "F" is motor size it says nothing about fuel.
Or like Mike said run on methanol and it would not be a "gas" boat.
One thing is for sure either way it gets handled people will get pissed.
How about this...
You bring your "F" nitro boat to a race but they don't...