Wetsuits are typically constructed of neoprene, a synthetic, waterproof rubber that is flexible and insulated. Wetsuits insulate the athlete by trapping a thin layer of water between the neoprene and the skin to reduce loss of body heat. The suit also provides warmth by separating cold water away from the skin. Sewing the suit is necessary if a hole or tear is present because this degrades the insulating process by allowing water to seep through. Holes and tears can cause the wearer discomfort due to poor fit and loss of body heat.
Clean the wetsuit with water and mild soap, especially the area that needs sewing. Wipe with a towel and dry completely.
Apply neoprene cement to waterproof the repair. Apply throughout on both sides and allow to dry completely.