Ok...so it?s late over the pond here in the UK and I?ve had a few beers. Added to this, I?d imagine there is a simple explanation for my question and I realise I could probably find the answer in a more sober state, but hopefully someone can answer this quickly...
At cruising speeds I have a prop slip of about 5 or 6, but at 55-60+mph it reduces to about 2 or 3. Someone please explain this.
One side of my brain is telling me that the boat is more efficient when running high up and next to no hull in the water, but the other half is telling me that some of the prop is breaking the surface. Even if it wasn?t, why would it change, assuming it is getting an uninterrupted flow of smooth water ?
Two known and proven figures (from screen shots and pictures I have are as follows;
Drive=1.47
Prop=19?
Rpm=2380
Gps speed=27.6 mph
Drive and prop as above
Rpm=4680
GPs speed=55mph
Thanks.
At cruising speeds I have a prop slip of about 5 or 6, but at 55-60+mph it reduces to about 2 or 3. Someone please explain this.
One side of my brain is telling me that the boat is more efficient when running high up and next to no hull in the water, but the other half is telling me that some of the prop is breaking the surface. Even if it wasn?t, why would it change, assuming it is getting an uninterrupted flow of smooth water ?
Two known and proven figures (from screen shots and pictures I have are as follows;
Drive=1.47
Prop=19?
Rpm=2380
Gps speed=27.6 mph
Drive and prop as above
Rpm=4680
GPs speed=55mph
Thanks.