When confronted with the doctored results, Thomas told investigators, “Yeah, that looks bad,” the Justice Department said. She suggested that in some cases she changed the tests to passing grades because she thought it was “stupid” that the Navy required the tests to be conducted at negative-100 degrees Fahrenheit (negative-73.3 degrees Celsius).

Having spent much of my life in submarines, however, I have found that the oceans are not simple contained structures. As we traveled the ocean bottoms, we encountered streams and currents within the ocean structure; therefore, temperatures varied despite constant depths. One of the most surprising was entrance into the Mediterranean from the Atlantic Ocean. At constant depth, the temperature dropped almost twenty degrees. Yes, it was colder in the Med than in the Atlantic Ocean at the same depths.

That seems like such a dumb reason to falsify data. It's not saying that subs are going to suddenly be operating in impossibly cold water, but that they need to withstand large variations in temperature without the hull warping. Like the reasoning behind why space shit is so over-engineered.