I suppose for guys more into long baggy swimwear, you can get away with wearing your boardies as shorts with a t-shirt and call it a day. You are ready to peel off your shirt and go. However, as you can imagine, I am not a baggy swimwear fan!
Do I normally throw a speedo on everyday in hopes of a quick dip? No…but if I think I may have an opportunity on a special day or outing, I am always prepared. I have no shame in packing a little bag full of options: speedos, squarecuts, thongs…..just in case.
But really, the most practical way is to just find a nice suit that makes a comfy pair of underwear for the day that you can strip down to. A nice comfy speedo or squarecut easily fits under a pair of shorts, absorbs moisture and sweat, and can be perfect if you end up getting wet 
I find that if there is an odd chance of that happening, I will wear a nice squarecut just in case. That way I can have a hot suit ready to use that will dry quickly. At the same time, it is decently modest depending on the company and atmosphere. I don’t have to worry about being too inappropriate in the wrong setting. If they don’t like my tight little trunks…too bad
It never hurts to be pepared…and since I usually wear tight underwear, this is not really an adjustment for me. Anyone else out there do something similar?
MMMMM – now I’d love to catch you wearing those!!!!