Nothing makes me more nervous than the typical boat's water system. Visions of explosive lumbo trickitis emanating from the lower blowhole, coupled with world class cramps or worse has generally discouraged even my most trivial usage of boat water. I would use it to wash dishes, or take a shower only if there was enough chlorine in it to bleach your hair Jean Harlow white, and sear your nasal cavities. In general, if you haven't make a serious investment in filters, disinfecting systems, and chemicals I think it should never be used for drinking. I know it's an audacious thing to say about your boat's expensive water system, but I think it's the truth. Just look at all the news stories about near death experiences, and severe illness boaters have had after drinking boat water. What? There really aren't any? Why I was sure I would find some. But I didn't, and I know why.