Chine walk, what it is and tips on what to do about it.
I borrowed this post from Jimboat to help some of you guys understand it and tips on what to do about it. EP
performance vee hulls, and particularly on vee-pad hulls. The design & setup of the hull and the weights & power have everything to do with the hull's susceptability to chine-walking.
As the hull accelerates, lift increases and the wetted running surfaces that are required to support the hull are reduced (more Speed = more Lift = less Surface). As the speed increases throughout the velocity range, the hull often gets to a point where the lifting surfaces become very much reduced and the hull is now “balancing” on a small area of the vee-portion or the “vee-pad” of the hull. When that surface becomes sufficiently small, it becomes very tricky to “balance” the hull on its vee or pad. The result is a rocking of the hull from side-to-side. This rocking can tend to get a little more extreme with each motion, and so the “balancing” must then be provided by additional driver (steering/throttle/trim) input in order to maintain the hull in a balanced state.
With some driver input, the condition can be stabilized. With changes to hull setup and/or changes to the driving technique the condition can be alleviated.
Note that the notion that chine walking can be “driven through” without making adjustments is a dangerous approach. Make the proper setup changes first. With experience, you can then learn to make the subtle steering, trim or throttle adjustments that might control the condition – but don’t try to just blast through the onset of chine walking, as this usually ends up to be a very wet conclusion!
Chine walking is predominantly characteristic of vee-hulls with deep Vees (more deadrise), hulls with deep or narrow running pads and hulls, with a Veed pad or no pad (straight vee). These bottom designs are just more inherently difficult to balance at higher speeds. Another contribution to chine walking can be seen at higher speeds from "propeller slap" (usually seen more with props of fewer blades). As the prop turns, each blade enters the water and another exits the water. This irregular in/out of every blade, changes the dynamic forces at the location of the propshaft, repeatedly putting an imbalance on a hull that is trying desperately to balance on it's vee or pad, and ultimately initiates chine walking.
Setup of your hull and driver “seat-time” are the best solutions to the problem. Usually an alteration to the hull, or hull setup and/or modification to your driving methods (read seat-time) will improve the problem.
For hulls that do experience chine-walk, some established steps toward minimizing chine walking include:
1. Check & adjust steering
2. Use solid mounts
3. Clean Hull Lines
4. Weight balance of hull
5. Motor height
6. Propeller selection
7. Seat time (experience)
8. Minimize Trim Angle
Summary: Optimize Hull Setup and Driver "seat-time"!
