Swim diaper
Definition
A non-absorbent diaper designed to contain solid waste in water without swelling, required at most splash pads for non-toilet-trained kids.
Most splash pads — and essentially all paid splash pads, water parks and HOA pools — require swim diapers for kids not yet potty-trained. Regular disposable diapers swell and burst when wet, contaminating the water and forcing closures.
Reusable swim diapers (about $10–$15 each) are cheaper long-term than disposables. Pack at least two per kid for any splash-pad day.