Skis get lost in powder and you can spend substantial time looking for them. They can go a long distance under the snow and be very hard to find. I was skiing with someone last year who lost a sk. We had to have the ski patrol come and lend a ski, and then she rented skis for the day. Luckily, at the end of the day we went back to the same run, and someone had found the ski, and stuck it in the snow.
Until now, the only solution was powder straps -- long lightweight cords attached to the bindings which you tuck up under your pants. On a fall, they are supposed to float to the surface, making the ski easier to find.
But powder straps are a pain, particularly if you are using a gondola lift, as each time you take your skis off, you have to deal with the straps.
I have been looking for a solution. I considered some devices that are just coming out, such as Apple's Tile, which you can attach to a key ring or drop in a purse or attach to some other thing you lose, and then track with your smart phone. But Tile costs $20 each ($40 total), the battery only lasts a year at which point your need to buy a new Tile, I'm not sure how you would attach this to a ski, and whether they are sufficiently waterproof or not is unknown. Competitors to Tile are coming out, but have the same problems. Also they only work with Iphones and only some newer Android phones.
I then looked into Skiretriever.com, which is a device to attach to a ski and locate it with a separate handheld. But it seems that the battery is hard to replace, and from the website the method of attaching to skis seems clunky at best.
So I kept looking. I finally found RESQSKI.COM. This appears to be the answer! They are only currently sold in Europe, but can be ordered online -- about $120. I have ordered a set, and am installing them. I will test them out and post what I find, once we get some snow!
The device looks very well manufactured and thought out. It attaches solidly to the ski. What is best is that there is a switch to turn the battery on and off, so that there should be no problem with battery life because you only turn it on when you ski (or when you ski in powder). Moreover, the batteries appear to be easily replaceable, The handheld device to find skis is small and light, and should be no problem to carry.
I think this is a great invention -- assuming it works well, and it looks like it will.