Water-jet drive
I have a ali, jet boat made by Jettec, a company here in NZ, who make full size jet boats. Mine is the lesser known model about 1/8 scale. The more common size was 1/4 scale powered by 2 stroke motors. ( there is a electric powered version used by the canterbury university, for water studies, but that's another story)
My 1/8 scale is almost to heavy with brushless motor, ESC, LIPO batteries.
Would be better to use a small glow motor, but where I sometimes use it, not allowed to use IC motors.