This one looks quite cool:
http://www.nuwear.com/Cover-Male-G-S...ack_p_148.html
Quite important to have effective front coverage for a man for some modesty.
Of course, when is the right time to wear one of these? I just watched a film called 'Zombie Flesh Eater' where there is one scene where a woman went underwater diving in the Pacific in a white G-string. So diving in one of those garments sounds quite appealing....