Wetsuits are made from closed-cell neoprene with large, uniform bubbles that provide good insulating qualities. The neoprene is usually coated or lined with fabric or sprays to add strength and color, plus make it easier to slide into. Bare neoprene on the inside doesn’t slide on as easily, but does minimize water circulation within the suit.

Wetsuit thickness is primary to warmth. Thicknesses start at 1 millimetre (mm) and progress up to 9 mm, with the most common being 3 mm (warm water), 5 mm (temperate water) and 7 mm (cold water) or a combination of these.