In my spare time during a long career of professional flying, I spent the best part of 15 years having something to do with running an RAFGSA gliding club in my spare time (I ended up as the CFI). Twice per year we would mount a 2-week expedition to such as Sutton Bank in Yorkshire and, in 1973, we started going to Aboyne in Aberdeenshire. It was a pretty basic site then but the wave flying was magnificent.
It has to be said that we frequently encountered rotor at Aboyne. The surface wind could be calm and then, a few hundred feet after take-off, all hell would break loose. Fortunately, it usually did not last too long and then it was possible to tow up into the smooth wave system.
Sadly, one of my friends died in the rotor whilst towing a visiting glider. He was flying a Citabria tug, the glider got out of position and he hung on to him hoping that the glider pilot would sort himself out. That did not happen and he and the Citabria entered the ground at speed.
A previous poster opined that wave does not happen close to the ground. I was at Aboyne once checking out one of my Full Cat Instructors. The general wind was southerly but there was not a lot of it. The tug was a Beagle Terrier and we were in an ASK-13. We took off to the east and the tug pilot turned south almost immediately, crossing the River Dee towards Glen Tanar.
After not very long we stopped climbing and were barely staying out of the treetops. Robbie asked me what to do. There was nowhere to go so all we could do was hang on and hope that the rope didn't break. It didn't and at about 800 feet we and the tug were going up like there was no tomorrow.
We spent the next hour rocketing up to 12,000 feet with the lift off the clock, then pulling the airbrakes out and slipping back into the sink (wave bars are seldom more than 3 nms apart) and so down to 1,500 feet or so and then rocketing up to 12,000 feet again.
It has to be said that powered aviation still has very little idea of how to deal with wave. In 1964, it was realised that the gliding community had been using wave for years to its own advantage and so it was that the Carlisle Wave Project was launched. Met men and all sorts of interested parties gathered together at Kirkbride and launched lots and lots of gliders to accumulate data. There were many interesting stories including one of my friends who nearly died of exposure when he landed out in the middle of nowhere.
Incidentally, the man that got me into aviation got caught in wave and didn't know how to deal with it despite a long and illustrious career in the RAF in WW II. He found himself on top of a large hill in SW Scotland in Miles Messenger G-AJOD on 05.11.52.
It is always better to learn from other peoples mistakes for you simply do not have enough time to make them all yourself