A dry suit is a specialized waterproof garment worn by divers to keep them completely dry in cold or contaminated water. Unlike wetsuits, which allow water to enter and use body heat for insulation, dry suits seal out water entirely. They typically consist of a waterproof membrane, integrated boots, seals at the neck and wrists, and a zipper for entry. Dry suits are crucial for diving in extremely cold conditions, contaminated water, or situations where staying dry is essential for safety and comfort.