Tank fill switch capabilities are pretty standard on all major watermakers. I usually don't install them on smaller cruising boats though. Weight is usually an issue with smaller vessels and carrying around full
tanks of water means a lot of added weight. Many times people who are just island hopping only fill their tanks partially enough for two or three days and then use the
watermaker to top off what they use. On average people with watermakers use 5-6 gallons per day. So for two people that might be 30-40 gallons every three days. Replacing that 30-40 gallons every two or three days is easy. If you have say 200 fresh water tankage it's silly to carry around the full 200 gallons at 8 pounds per gallon which is 1,600 pounds of water. Drop a 1,000 pounds. Crossing oceans and sailing to far flung out of the way places is a different story. This is just part of the reasons you should actually talk to a few
watermaker reps before you decide to
purchase a watermaker. There is no one size fits all watermaker. Everyone's personal use will be different even on identical boats. You can buy too small of a watermaker and yes you can buy too large of a watermaker. Finding what best suits your needs and your boats capabilities is an important step too many people fail to undertake when pricing watermakers.