October 29, 2007: The U.S. Navy has relieved the commander of the nuclear submarine (SSN) Hampton after it was discovered that daily checks of reactor coolant water were not made for over a month. This was covered up by later making entries in the records to reflect that the tests had been done. These daily checks of the water chemistry are used to discover if there is any corrosion in the pipes that could cause a loss of coolant, and a shutdown of the reactor. The commander of the sub is responsible for insuring such safety checks are done, or catching failures to do so. Other members of the crew were punished for either not doing the checks, or not catching the error as part of their duties. The daily tests were supposed to be checked by the sailors supervisor, and later by the captain. The error was caught during a mandatory inspection of the subs records after its latest cruise. These double checks are meant to catch things like this, as well as more subtle problems that the commander would not be held responsible for. The U.S. Navy is pretty fanatic about safety aboard submarines, and has the best safety record of any nuclear submarine fleet. So far this year, four commanders of American nuclear submarines have been relieved for various leadership problems. The U.S. has seventy nuclear subs in service. There has been an increase, in the last decade, ship captains getting relieved. There have been studies of why this is so, but the senior leadership believes that it's better to relieve too many, than to relieve too few. It's a custom that has always been the hallmark of a superior combat fleet.