Prop diameter versus rooster tail.

[Jbar]

Does anyone have any input as to how prop diameter/pitch changes the height or shape of the rooster tail typically found at the 22'off wake?

Thanks

[skiinxs]

Does anyone have any input as to how prop diameter/pitch changes the height or shape of the rooster tail typically found at the 22'off wake?

Thanks

Props certainly do affect roostertail. I have no empirical data to support specifics, but it would be an interesting testing process involving several skiers to weigh in on their opinions of each prop's effect on roostertail, and wake in general at all line lengths. Actually this sounds like a good potential article for Water Ski magazine. My gut feeling is that the amount of stern lift or bow lift generated by any specific prop design would have a great deal of effect, and the shape and turbulence of the water column behind the prop would be a large factor. Number of blades, rake of the blades, shape of the blades, amount and location of cup, thickness of blades all affect both the stern or bow lift and water column, as well as efficiency. Before the CNC props became popular, it was common to have very different performance characteristics from different props of the exact diameter, pitch, cup, manufacturer (exact part number). My experience with the CNC props is that they are much closer when looking at the exact same part number, assuming that they have not been damaged or repaired. Another factor when evaluating different props is the intersection of the roostertail and the point where the wakes from the rear corners of the hull come together at different speeds and line lengths.
Dave

[Mikeski]

on my 211 I installed the acme 1234, 14.5" diameter prop which destroyed the slalom wake. At 28' off it was like skiing behind a jet boat with water balls the size of ping pong balls coming up to my waist. Not wanting to start skiing with a cup to protect my man parts I changed the prop back to a 13.5" diameter. In general a smaller prop will give you a cleaner wake at speeds over 30mph.

[EntiatSkier]

What speed do you ski at? I used to ski at 22 off at 32mph and that rooster tail made it one heck of a ride. But when you bump it up to about 34mph or 36mph, it is like nothing is there! I ski at 34mph with the original prop that came with my boat at 22-off and its not noticeable. 1-2mph can make a HUGE difference!