Submergence test procedure: During vehicle submergence, at least 1 window per row of seats shall be capable of being fully opened after the vehicle enters the water up to 2 minutes. The container shall accommodate the vehicle with sufficient dimensions to allow it to remain in water for 2 minutes without contacting walls or floor, or alternatively open-water test sites may be used provided they comply with test conditions; freshwater lakes, reservoirs, and saltwater bodies are not permitted. The vehicle’s master control switch shall allow window operation; the vehicle mass shall be unladen kerb mass. The vehicle shall be lowered into water at a horizontal angle of 0–10 degrees. Time zero is when lowering straps become slack and the vehicle starts floating freely. The vehicle shall remain in water for 2 minutes from T0 and shall not contact the container floor until fully submerged. After 2 minutes, the window shall be capable of being fully opened using a remote system, or for vehicles equipped with automatic window lowering systems, windows shall automatically lower within 2 minutes. Alternative subsystem tests demonstrating window opening functionality under submerged conditions are acceptable in agreement with the approval authority and the designated technical service.