Lunchstop is the first significant rapid after the put-in. The river right channel swings left around rocks that jut out from the bank. The river drops over a few small ledges that make good playspots for sidesurifng and front surfing when the flow is up over 2,000 cfs.
Rocks then jut out from the left side bank on the right channel and the river swings around them. At the bottom of this small drop is a long, flat wave that is good for surfing above about 1,500 cfs.
Below this is a rock that is out of the water at levels below about 2,500 cfs. Above 2,500 cfs the downstream side of this rock forms a great wave hole. You can do lots of playing here. Front surf, spin, sidesurf, enders, limited only by your ability and the water level. Best level here is around 5,000 cfs, IMO.
Big pool below here and a giant eddy that you can use to get back to the flat wave. This allows you to ride the 2nd half of the rapid until you get tired. Save some energy for the rest of the run!
Above 6,000 cfs or so Lunchstop pushes Class III levels as the different parts all blur together.