Collins-class submarine

Collins-class submarines are big ships that travel under the water. They are like submarines, but bigger and quieter. They have special parts that help them stay quiet, like special sound-absorbing materials that keep the noise of the engine from coming out. They also have engines and other special parts that help them move quickly and quietly through the water. They are used by some navies around the world, and they can stay underwater for days or weeks at a time.