Freshwater systems are relatively straightforward and not too difficult to maintain if you understand a few basics. On small boats, a system can be as simple as a tank and a pump that comes on when a faucet is opened. Systems on most yachts, though, are a little more involved. They consist of one or more tanks, often with level monitors, feeding through a sediment filter to a pressure pump. The pump charges an accumulator (bladder) tank to maintain pressure without continuously running the pump. The pipe or hose from the accumulator then feeds to a manifold to supply cold water directly to the toilets, showers, tubs, lavatories, galley sinks and ice makers. It also feeds to a water heater, fitted with a temperature/ pressure relief valve for safety, to supply hot water to the showers, tubs and sinks. On larger yachts, there may be a connection to the washdown hoses and even to the firefighting system to avoid the damage that would result from spraying salt water inside the yacht in the event of a small fire.