1) weather analysis
I'm a hang glider pilot, but this applies to all wind sports – windsurfing, kiteboarding, paragliding, sailplanes, possibly even surfing and skydiving.
These sports require weather analysis. Is the wind blowing from the right direction? Is the cloudbase high enough?
Some weather analysis tools exist like http://www.xcskies.com/ for hang gliding and paragliding, but they're not perfect to say the least.
I still spend too much time looking at various charts and forecasts in the summer, and then waiting on site once I arrive and the weather conditions aren't right. If you can make me wait less on my precious weekend time, you have my money.
Participants of these sports pretty much accept the current level of technology to be as good as it gets, because there are very few meteorologists who could create new, better weather models, and at the same time be either interested in doing that for free or have the technical and business acumen to make it a business. So pretty much everyone uses the RASP model and weather data off many disparate websites.
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2) flight instruments
Hang gliders, paragliders and sailpane pilots use special devices that combine a variometer with GPS and some stored map data to record flight paths, show airspeed, descent rate, etc. These are small, like a fat iPhone 6+ with a calculator-style screen.
The company producing the most popular ones is Flytec. I'm not sure how they get away with selling a simple device that runs on two AA batteries for $400-$1000. Maybe they have some key patents... though they are not a monopolist, there's FlyMaster for example. Flytec's devices are pretty much the same as those they were selling 10 years ago, they are cheap to make and should not cost that much.
There's room in the market for a significantly cheaper and/or more magical device. By magical I mean stuff like "go this way to get into the lifting air you've just lost", or "fly faster/slower to maximize glide ratio".
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3) weather mapping drone
When the wind hits the mountain / ridge at a certain angle, hang gliders, paragliders and sailplanes can easily soar next to that mountain. The wind also needs to be in a certain speed range etc.
Sometime we pilots want to check if that mountain over there could be flyable. It looks like it might be soarable, but to verify this, we need to drive up the mountain and launch a live person in a glider from there. That's a huge waste of time, and because often such roads are privately owned, there's a lot of hassle in getting permission to do that. Landowners are afraid of the liability (which we legally waive but it takes time to explain and verify), and we don't even know if the mountain is soarable at all, we can only guess.
It would be nice if we could just launch a drone which would fly around and record wind direction and speeds at various locations and altitudes.
The same technique could also be used to better understand existing flying sites, OR to find thermals (invisible pockets of uprising air which gliders need to stay up in the air for long period of time). And this is #1 thing we want – more found thermals, more airtime.
So maybe it can be a sort of follow-drone that flies in your general area, telling you where the thermals are. You can tell you're in a thermal once you actually fly into it, but you're descending at 3 ft per second, so the amount of time you can fly searching for thermals is limited.
Because you're flying a glider, the follow-drone can be a glider too with just a small auxiliary engine, you don't need too much battery power.
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So there you have it. Wind sports are technologically underserved because the market size isn't very big, but the pain is real, and it's #1 reason preventing more people from participating. Maybe some of the weather / hardware solutions you develop might also be applicable in other fields. Maybe you already have a solution that is fairly easily adjustable to wind sports (esp. drones).