Conventional submarines, also known as diesel-electric submarines, are underwater vessels that primarily use diesel engines for surface travel and electric batteries for submerged operations. They are designed for stealth and can operate quietly, making them effective for various missions, including surveillance and anti-submarine warfare. These submarines are typically smaller and less expensive than their nuclear counterparts. They require periodic surfacing to recharge their batteries, which limits their underwater endurance. Conventional submarines are widely used by many navies around the world, including those of Germany, Japan, and Australia.