Don't over worry about water. 1) verify that tanks are full before you leave the dock. 2) monitor water use, party by guages if they work and also by when a tank runs out. 3) know where you can get water and don't take chances when you are on your final tank.
Keep track of
Warren S/V Scuba Doo Lagoon 50 (winner of best crewed yacht under 55 feet at the St. Thomas crewed yacht boat show).