Sailboats carry a very limited amount of water on board, yet they float in a near limitless amount of water. When doing tasks such as washing dishes or bathing, why use the limited water supply that you need to use for living activities such as drinking?
This led me to the idea of tapping into the limitless water that we float in for menial tasks that need to be carried out as part of our daily lives. Activities such as washing dishes are very water consuming and could be easily performed with saltwater followed by a freshwater rinse.
Getting saltwater into the galley to clean dishes is easily accomplished via different methods. The first and simplest is to haul up a bucket of seawater and bring it into the galley. This is easy and takes almost no installation. All you need to do is carry a bucket that you can use to scoop up some seawater. After the dishes are washed, they can then be rinsed with freshwater and put to dry.
This system is simple, but grabbing a pail of seawater every time you want to wash something is a bit of effort. When washing a bunch of dishes, this would be just another step in the process. What about when you are washing one cup after some tea? Are you really going to grab a pail of water to clean just one cup? Truth is you will probably justify in your mind that you wouldn't really use too much water from the tanks, making it ok to wash this one cup with freshwater instead of saltwater. After a long journey, the total number of "just one" will add up and will have a direct impact on your freshwater consumption.
With a bit more installation and work, you can plumb a saltwater line into your galley. This will remove the need to grab a pail of seawater every time you want to wash up. Instead, you only need to open the faucet and let seawater run into the sink just like your tank water would. How you pump the seawater will depend on how you pump your freshwater.
You want to make the pumps equivalent, otherwise you will find yourself favoring the pump that is easier to use. If you have an electric fresh water pump and a manual salt water pump, you will find reasons to justify using freshwater as you scrub the burnt on food off the bottom of the pots. All this time, freshwater is being wasted by a task that is better suited for saltwater simply because it is easier to have an electric water pump run instead of a manual water pump.
If you have a manual fresh water pump, you can either make the salt water pump manual or electric, as you will have to work for the fresh water, making you very strict about its use. If you have an electric freshwater pump, you will need to install an electric saltwater pump to ensure that you will use it.
This then begs the question about how to deliver the saltwater to the galley? Should you install a new faucet, or use an existing faucet that you have already present? Once again, the ease of the saltwater side should be equivalent to the ease of the freshwater side or you will find yourself wasting freshwater because it is easier than using saltwater.
Imagine you have a small tap that dispenses saltwater over a large double sink and a large goose neck faucet that can be moved from sink to sink that dispenses freshwater. Guess which one you will use more often? To make life easy, lets simply tap the saltwater plumbing into the existing galley faucet!
While sailing, you will not be plugged into shore power so your water heater will not be working. On a long journey, the water heater will cool down and your hot water and cold water sides of the faucet will all dispense cold water. This opens up an opportunity to simplify our lives. By teeing in a saltwater line into the hot water side of the faucet, you can easily have saltwater flow out of the faucet by opening the hot water tap.
This makes life very easy, to wash dishes with saltwater, all you need to do is open the "hot" water tap. This will grant you endless amounts of water as you are floating in an ocean of seawater! Once the dishes are clean, you can close the "hot" saltwater tap and open the "cold" freshwater tap to rinse the dishes clean.
Now you have saltwater and freshwater readily available to you in the galley with the simple turn of a tap. Using saltwater instead of freshwater will greatly extend the length of time you can get out of your water tanks!