Unfortunately slight flow variations of just a couple hundred cfs make or break waves that time of year. The river should be bottomed out. some years thats good - others not so much. The truth is you wont find the "unicorn wave" with sweet eddy access and sandy beach. But you will find catch on the fly all the way down. There is usually a nice trail on one side or the other of the river. So, start watching for waves and then find a beach within a mile and hike back up. But surfing and rafting is tough that time of year. The current is slooooow and the kayaks will play leap frog all trip. Nights will be long, days will be short.... River miles will be tough to come by in a raft. You will need to keep moving. Just saying.