Swimsuit: World Aquatics-approved suit (textile-only since 2010); men's suit max from waist to knee, women's max from shoulder to knee; Cap: mandatory event-issued numbered cap (high-visibility colors); Goggles: permitted (anti-glare recommended for sun)
Why people argue about this
People often assume that since textile-only swimsuits are mandatory in open water swimming due to health and environmental concerns, it must mean swimmers can't use fins or electronic aids at all. But actually, these restrictions apply only to equipment directly worn on the body, not to accessories like fins or electronic timing devices used during races.
