How much SKIN should a Christian woman or girl show in public (around town) or at the beach or resort ?

To tell you the truth, I don't go swimming for this very reason. If I do it's in female company and in a one-piece. I don't want guys to be looking at me. We are not supposed to stumble our brothers. It is a sin to lust, so I refuse to be the cause of such a sin. God calls us to be modest. I want self-respect as well. This is my personal choice and I don't think that I'm altogether wrong.