Unlikely but in theory it is possible for the drive shaft to have a slipping pinion gear (exactly how I don't know) or even worse and less probable, the driveshaft could be slipping in the power head where the splines connect. You would think that would make a horrible noise.
When the boat revs increase and the hull seems to lose power, do you hear ventilation or blow out ? It should be obvious.
When the boat revs increase and the hull seems to lose power, do you hear ventilation or blow out ? It should be obvious.