Was not dared by anyone but once when younger, at a crowded beach on a sunny day, the waves were choppy enough to make the water turbulent. I slipped out of my swim suit under water, dropped it and would swim away and back to try to find it, remaining naked (keeping (mostly?) hidden under the water). A few panicked moments when the waves had moved my suit away from where I left it. I was thirty yards or so from shore.