Heyhey, I'm around! Been crazy busy so haven't been on WW lately. I'm assisting a commercial photographer out of New York these days, so I've taken a step back from shooting wake stuff myself.
Bess is on the money. Light meters come in very handy sometimes, but experience is the most important. Light meters won't fix the light for you though... all they do is measure how much light there is present.
It's important as Bess says to understand how a meter works and how to read its output. Also, understand the difference between Incident and Reflected readings. Reflected readings measure how much light bounces back off of an object, and give you the exposure you'd need to dial in to make the targeted object 18% middle grey. So, if you're trying to take a picture of snow, and you trust the reading right out of a reflected light meter (like the one built into almost every camera), the snow will appear grey. Knowing how the meter works, you can open up your exposure two stops (from middle grey to light grey, and light grey to white with detail) for proper snow exposure.
Incident meters (those with the little white dome) work differently. They measure how much light hits the meter directly, instead of how much bounces off of an object. So, you can use an incident meter on a white ski slope or on black lava fields and get the correct exposure. HOWEVER, the light falling on your meter must be the same as that falling on your subject. Probably will be the same if your subject is fairly close... but for landscapes where it might be cloudy over you and sunny in the distance, incident metering won't work so well.
Incident meters are fantastic for working with strobes. They allow you to measure the light output of each strobe unit, and calculate ratios in order to set up lighting patterns, among other things. Reflected meters are fantastic when you want to make things a certain tone... for example, if you're shooting B&W film and want to make sure something in a scene is dark grey, while something else is white with detail... you can measure that. Also by taking input from both the incident and reflective meters, you can measure tonality and also difference in tonality.
This is kind of a long answer to a simple question. I hadn't seen the other thread previously, but looking at the images in it, a meter won't help much. You can expose the rider properly, but the background will be overexposed. Quite simply, a meter will just allow you to read the light with a little more accuracy. They won't however change the direction of light for you, or even out a discrepancy in light.
Hope this helps!