Getting into data logging for MX and have recently picked up a LitPro data logger which the majority of the pro teams use to monitor lines, speed and lap times.
This thing does 20 samples a second and picks up speed, accel, deccel, G Force. Seems like this could be pretty interesting to see how different settings translate to different forces on the body. You could also see where/ when the ski is accelerating after the ball as well as your coast into the ball.
You can take overhead shots of the course and overlay your run onto this so you can see how your lines compare to the course. As well as compare runs to different runs to see how your data from each run compares to the next.
The major 'snag' with this device is it isn't waterproof... but it's about the size of a deck of cards so I'd think you could put it into a waterproof phone holder and attach to your jacket somehow.
Here's a screen shot from a recent ride. The colored line is speed and the small bars are the decel rate.
Curious what you all think! Seems like could answer some questions I've heard asked before about how fast are folks really going across the wake as well as cornering speeds as line lengths shorten.
Given I live in MN I might be willing work out a loan program if someone with some skills wants to try this out during my off season. Would just need some mutual agreement about protecting it from damage