Albatrosses do it. But calm air days = sled rides in sailplanes.
Even then the warmer air rises over the cooler air it's converging with like it's going over a ridge, so it's not really still. In NW Florida, If you could get high and stay high early enough in the spring on a rare early hot day just as the sea breeze started kicking in you could ride around in it, but as soon as you got below the rising air you were looking for a place to land- at least the maritime air was pushing you towards the land. The nice thing about the stretch from Mobile to Pcola was that you couldn't swing a stick without hitting a landable field.
The club in Hampton Roads will go out to the military aviation museum in Pungo and fly out of there if some of the weather geeks think the conditions will be right for it.
This past summer, I joined the glider club out in Front Royal, VA. It has a great mix of thermals, ridge, and wave.
Unfortunately, we are have issues with our wave window right now. The FAA wants 45 day notice to go into Class A and yeah, no one can predict wave that far out. So right now we are capped at 18,000 ft.
It's a great club 2 ASK-21s for training a sprite and a discus for fly fun flying. Plus many private gliders.