I used to fly R/C gliders at this great place on the ocean here in LA. It's a park that overlooks the Pacific Coast Highway, and I'd fly R/C combat w/ my flying wing Zagi there. There were some dynamic soaring guys that got insane speed and e out of their planes. The ocean itself was across a highway, a beach and about 1/4 to 1/2 mile from the top of this hill. I'd see guys with these carbon fiber gliders whip themselves into a fury going back and forth, getting faster and faster until they'd point their plane west and fly out over the beach and actually over the ocean, then turn back. They'd be down to 10-15 feet altitude by the time they hit the beach again but the heat coming off the sand would let them thermal just enough to get the altitude to get to the air vortex that fed this cliff face, then they'd be climbing and be back in the pattern.
It was amazing energy management, if anyone here lives in LA, take PCH to the road that goes up into Pacific Palisades that's right next to Will Rogers park and go up to the park that overlooks the ocean.