Associated with, but not part of, the Eden Naturopolis ‘country’ (I think it’s reasonable to say that it’s practically a nation within SL, and with the added advantage of not having a military! 🙂 ) The Fruit Islands are, indeed, islands around which it’s possible to do a lot of sailing.
I’m not going to provide slurls, as they aren’t, strictly speaking, naturist, but they’re probably categorisable as ‘naturist friendly’. I never pop my clothes on when visiting, and although I’m not much of a sailor, I do like to take whatever boats I can find out onto the water and tour whatever I can find. That said, do take care not to offend. If you’re tp’ing in, pop on a swimsuit at least until you determine the state of play, then slip off the speedoes or bikini as you see fit.
I took a small motorboat out onto the water, and enjoyed just letting the scenery slide by. It’s a location I’d recommend to anyone, with the added potential (if quiet) to go nude if one wishes.