If they're visible then I guess it's not appropriate to be seen doing a responsible/professional job; pilot, doctor, lawyer et al. Just look at that BBC video shot of David Beckham in St Georges's chapel (at the royal wedding) last Saturday, he comes across as a thug dressed in formal clothing chewing gum. I personally do not like tattoos, I cannot understand why people wish to permanently mark and disfigure their bodies; but that's just me. I know many airline pilots who have discreet one's but well hidden from public view. Act in haste repent at leisure comes to mind.