Scuba equipment is not commonly used in civilian commercial diving, but is often employed by scientific, media and military divers, sometimes as specialized equipment such as rebreathers, which are closed circuit scuba equipment that recycles exhaled breathing gas instead of releasing it into the water. The recycling of gas makes rebreathers advantageous for long duration dives, more efficient decompression is possible when the gas mix is adjustable, and observation of animals in the wild is facilitated due to the lack of noisy exhaust bubbles. These characteristics also make rebreathers ideal for military use, such as when military divers are engaged in covert action where bubbles would alert the opposition to their presence, or when performing mine clearance where bubble noise could potentially trigger an explosion.