The development of the pneumatic fenders developed for submarines and other vessels is the hydropneumatic fenders. The hydropneumatic fenders are partially filled with water and air and they are equipped with a counterweight to keep them in a vertical position. This ensures that the submerged part of the hull is protected properly from the fenders at any time. The hydropneumatic fenders require special installation techniques. The features are the following:
- Underwater contact area
- Low hull pressure
- Movable
