Fresh Water—Of course, a critical resource at sea is fresh water and most long-distance cruisers have a watermaker on board. While it is possible to rely on shore-side water taken in tanks if you don’t have a watermaker, the careful rationing and salt-water washing entailed can be a deterrent to many cruisers. But even with a watermaker, care is required. On Celebrate, we have a 150-gallon freshwater tank. When the gauge reached about half-full we would run the watermaker and refill it. That way, if/when the watermaker failed, we would still have 75 gallons onboard which could get us to our destination safely. We also have a saltwater foot pump at the galley sink to make it easier to get seawater when needed.
Our watermaker runs on 120v which means it will only run when the genset is running. On our previous boat, we had a watermaker which ran on 12V so it would run on batteries. From a practical viewpoint, even the most efficient watermaker is likely to exceed the output of your solar or other auxiliary power source so you’ll need to run your engine or genset anyway to make up the loss. This also means that even with an efficient 12V watermaker, you will need to ration water if the primary charging system fails (engine or genset) as you’ll have to cut back on watermaker use.
Another point on water…not all of your destinations have water available. When you are at anchor in the crystal-clear waters of the Caribbean or Fiji, for example, you can run your watermaker. When you are docked in Bali, for example, the water on the dock is not potable and the water in the harbor is too dirty for watermaker operations. Although you can always purchase containers of drinking water, this leads to the interesting turnabout where we had plenty of water when we were at sea but had to be much more careful when docked.