Thanks for the reply,
1987 Ebbtide 16' bass boat
QL Propellers - C SERIES - 12.5 X 13 A3r Propeller
to
Michigan Wheel 12-1/2"X13P Vortex 3 Blade Aluminum Propeller
I assume it was ventilation.
first prop would do 30 mph(before it got chipped and dinged up)....2nd not over 12 mph....once at 12 mph it would gain rpm but not gain speed.