A watermaker is a device used to obtain potable water by reverse osmosis of seawater. In boating and yachting circles, desalinators are often referred to as "watermakers". The devices can be expensive to acquire and maintain, but are quite valuable because they reduce the need for large water tanks for a long passage. The term watermaker may also refer to an atmospheric water generator, a machine that extracts potable water from the humidity in air using a refrigeration or a desiccant. Varieties Many versions are used by long-distance ocean cruisers. Depending on the design, watermakers can be powered by electricity from the battery bank, an engine, an AC generator or hand operated. There is a portable, towed, water-powered watermaker available which converts to hand operation in an emergency. Water requirement There is great variation in the amount of water consumed. At home in the United States, each person uses about 55 gallons (208 liters) of water per day on average. Where supplies are limited, and in emergencies, much less may be used. Typical cruising yachts use from 4 to 20 litres (1.05 to 5.28 gallons) per person per day, the average probably being about 6 litres (1.59 gallons). The minimum water intake required to maintain body hydration is 1.5 litres (0.4 gallons) per day. The amount of water that is required for a person to consume is dependent on different factors. Some of these factors include weight, height and gender. Men on average needs a greater amount of water than women do. Popular brands of yacht watermakers typically make from 2 to 150 litres per hour of operation (0.53 to 41 gallons) depending on the model. There are strong opinions among small boat cruisers about the usefulness of these devices. The arguments may be summarised as: Pros A watermaker uses only a small amount of fuel to generate a large amount of water, eliminating the need for large, heavy water tanks. The user is independent of shore-based water supplies, which is especially important in remote area. They provide safe water when shore-based water is of uncertain quality. Some designs are portable and can be converted to manual operation in an emergency. The hand-held unit offered by one manufacturer and the towed water-powered watermaker offered by another manufacturer can be transferred to a liferaft in an emergency. Cons They are expensive: Indicative costs are US$2,000 for the manual type, US$3,000 for