Pool etiquette: shower naked before you swim, and no shoes past the line

Icelandic pools require a full shower without a swimsuit before entering, in the communal changing room showers, and attendants enforce it; it's about the chemical-free water, and nobody looks. Shoes come off at the marked line in the changing room. Hot tubs are the conversation spot; the hottest one is for the regulars who've built up to it. Tipping isn't done anywhere in Iceland. Icelanders use first names for everyone, including the president.