First time winterizing the fresh water system on my own. Going to try and avoid the typical questions you guys get. I've read previous topics, but just wondering if you guys can help answer some questions regarding my situation. Eventually I am going to install a bypass for my hot water tank, but for now I am just going to connect my in/out together. Put some pink into my fresh water tank and run it through all the lines. Simple enough. My questions are regarding the black hoses (See pic below). How exactly does this system work? Do I need to pull these lines off the hot water tank as well to drain out? I realize they go to the engine to heat the water when running, but hoping someone can explain how this works a little better. I will be letting my marina winterize the actual engine, so is it up to them to make sure these black lines have no water in them? Also, looks like my drain for the hot water tank is pretty high up from the bottom (Far Left corner of picture). Looks to me like quite a bit of water will be left in the tank, that's fine to let that much water to freeze? Thanks in advance!