What do you wear when you cant be nude but want to be...
lightest pair of shorts I own, which are mesh and slightly see thru. My wife wears a sheer cover up. If you're up close to us ... you can see through them but from the sidewalk ... can't see anything. Backyard ... always naked. ;D
A kilt works well and they're becoming a little more common than they used to be. The Utilikilt or SportKilt works great for American men. It's lighter and more versatile than a traditional kilt and usually has pockets. No underwear required, expected or accepted ;-). Easy on, easy off and the next best thing to being totally nude.
It depends on circumstance. Most of the time T-shirt and shorts unless swimming then it is a pair of speedos as like many others I can't abide clingy shorts. I have a brief pair of trunks, substantial thong which I sometimes use where topless but not nudity is OK. Resorting to thongs and other micro-swimsuits shows just how ridiculous not allowing nudity can be.