I have been to 3 nude beaches, in spain, and trust me getting a boner is really hard(no pun) to get because at everybeach there is always like 10 times more fat, old people then there are young hot ladies, so any time of hard on you might get is quickly distinguished by the old fat (totally unshaven, I actually never saw dick or pussy at this beach because no one shaves!!!, except for this one occasion, I saw a really fuckin hot chick around my age, pube less, walk right in front of me).