In non-nuclear ships, they keep the drinking water and diesel or jet fuel in the same tank. They rely on the fact that the fuel floats on top of the water and doesn't mix (much) except in very heavy seas. What they fail to tell you is diesel is a very dirty fuel oil. Just because the hydrocarbons and water don't mix, doesn't mean that the other nasty stuff in the fuel doesn't transfer to the water at the fuel/water boundary. This goes on even today.
I used to hear from countless people who served on non-nuclear ships how they often tasted the fuel oil in the water, and smelled of it after a shower.
I used to hear from countless people who served on non-nuclear ships how they often tasted the fuel oil in the water, and smelled of it after a shower.