The Cote Sauvage - the Atlantic coast west of Royan is almost entirely clothing optional and there is also a second narurist beach on the estuary near La Palmyre but I have no personal experience of the latter.

The naturist /c/o beaches at Royan are lovely personally. I would be in La Palmyre the beaches are fantastic even the one on the Gironde Estuary is just perfect Golden sand, Waves to die for on the atlantic side, Perfect for Body boarding, some have a small bank of dunes which you are discouraged from using (Fencing) due to protection and then the back is nearly always Pine Forest. There is even a naturist site http://www.le-petit-dauphin.com/
Though didn't stay there. I seemed to remember that is a case of some beaches at the towns themselves are classed as Clothing Compulsory to cater for the English Market. I wasn't a naturist then but everyone happily co-existed together. if you want a beach that has hardly anyone on it go outside La Palmyre towards Le Mathes and cut through the Pine Forests easy walk the beach miles and miles of sand. we don't normally go to the same place twice, but we went to La Palmyre 3 times. family loved it. My daughter took her husband and her two children back there, he said it was the best holiday he had ever had. `sorry for going on but then again i am a little biased lol

Thanks both...very helpful.