Only part of Orient Beach is nude (the far end), however there are folks that stroll down the beach from the nude end to the dress optional end. We have been there twice (with standard American swim attire) and never felt out of place. My wife kind of enjoyed seeing the random nude stroller walking by (they all really needed swim suits!). There are restuarants in the area; our tour included a meal at one of them; much better than expected.
If you cannot handle a pure non-nude beach then you will have to stay on the Dutch side of the island. I cannot name any specific one, but I am sure that there are some. That said, the French side is the place to go.
05/89 NCL, Seaward, 1990 Carnival, Topicale, 1991 Carnival, Festivale, 11/93 Wind Star, Wind Song, 01/95 Celebrity, Horizon, 01/96 Celebrity, Century, 01/00 Celebrity, Zenith, 01/01 Princess, Ocean Princess, 01/02 Princess, Ocean Princess, 01/03 Celebrity, Summit, 05/04 Princess, Diamond, 01/05 Celebrity, Galaxy, 01/07 Oceania, Regatta, 01/08 RCCL, Voyager of the Seas, 02/09 RCCL, Voyager of the Seas, 01/10 Celebrity, Solstice