I dressed up a little bit when we dined at the CG but only because I wanted to (I don't get to much at home since dh and I rarely go to dinner without our 3 kids ;-) and I actually felt a little overdressed compared to others seated around us. Most had shorts and casual tops on. The only big no no would be a tank top. You'll find it varies a lot here but I would say a nice pair of walking shorts or capri pants and a top would be fine for a woman and a pair of nice shorts (khakis perhaps) and polo type shirt would be appropriate for a man.