Yeah, we have a watermaker and actually haven't yet needed to use the fills. Still w/o a water maker we had this in our last boat and we NEVER got diesel in our water tanks or visa versa. We also have a rain catcher setup so running the hose inside the boat; down hill, filtering it before it hits the tank (amazing how dirty rain water can be) we've never had a problem. No diesel hoses ever go into the boat! None, Nada, Zip, etc.

Fair Winds