Most charter companies are installing water makers now. They are a maintenance issue but in the last few years are much better. I find however that on a cat with 210 gallons we get water once a trip and don’t ration it. Normally that is at the dock somewhere mid trip so not much of a issue to spend 15 minutes topping the tanks.
One problem is that if a boat has a water maker and it’s not working or breaks charters get upset. Some even demand a boat swap.
G