Fitting a new water tank gauge
Boats are likely to have many instruments aboard, and one of the most useful is that which indicates the exact amount of fresh water in the tanks, especially if the boat doesn’t have a watermaker. But accurate water gauge reading has been a problem on every yacht I have owned.
My 45ft schooner Britannia has two stainless steel freshwater tanks amidships, one on each side. Like most yachts the outer shape follows the curve of the hull and the tanks are therefore broadly triangular shaped in cross-section, tapering to a point at the bottom.
This shape makes accurate calibration of water capacity difficult for most electronic measuring devices: when the device in the tank measures the water halfway down the vertical side of the tank, the actual capacity is much less than half – only about a third in Britannia’s case.
The remedy would have been quite simple, if somewhat crude, had my system actually worked. It would have just been a question of first determining the exact volume of water in the tanks by draining
