The dunes are extensive and the whole central section of the beach is nudist so you would have no problem wandering about naked. Be aware that one section of the dunes is a cruising ground late at night and even during the day so you may come across some interesting sights. Avoid the shrubby bit by the lagoon!
There are a fair few non nudists exporing the dunes but everyone knows it is a nudist area so you would never encounter any problems.
You might also consider the large beaches in Norther Fuerteventura.