 At the completion of work or a mission, the saturation diving team is decompressed gradually back to atmospheric pressure by the slow venting of system pressure, at rates of about of 15 to 30 msw (50 to 100 fsw) per day, (schedules vary).Thus the process involves only one ascent, thereby mitigating the time-consuming and comparatively risky process of multiple decompressions normally associated with non-saturation ("bounce diving") operations.The chamber gas mixture is typically controlled to maintain a nominally constant partial pressure of oxygen of between 0.3 and 0.5 bar during most of the decompression (0.44 to 0.48 bar on US Navy schedule), which is below the upper limit for long term exposure.