People don’t seem to understand the real meaning of clothing optional. It is not to be taken literally and doesn’t mean no-one cares what you wear. It means nudity is encouraged even if not compulsory.
The bottom line is that while no-one cares too much about the occasional lady wearing incredibly revealing swim wear, lots of men taking advantage of nudity not being compulsory by wearing swim shorts makes them look like gawkers and nearly all nude women will be quite uncomfortable with this. It’s more considerate to go nude.
We never pack a single swimsuit when go to Desire or any other C/O resort. There are very few places with that ease to waste wearing a bathing suit that is uncomfortable when wet and leaves tan marks.
About 8 years ago we took a long vacation: 4 nights at Hidden Beach Resort, 8 at Desire Pearl and the last 4 at Catalonia Royal Tulum (the latter only for adults, topless optional). I packed a couple of bathing suits for myself, but my wife didn't even consider something for herself. At the last moment, when we were checking out at Pearl, she realized that she would need one, so I went to the lobby shop and bought her the most daring g-string they had, of course without a top. I must tell you that she was very successful in Catalonia!
Regarding SusanAndDavid's opinion, I find it excessively and unnecessarily rude, which does not fit the spirit of Desire. I hope I never meet them personally.