Not just for long-distance sailors
Another common misconception is that watermakers are only for long-distance sailors. Even when coastal cruising, avoiding the need to ration consumption and plan around water refills every few days can be a significant advantage. Equally, the total amount of power used is surprisingly modest, especially for energy-recovery low voltage units, where producing 100 litres of fresh water typically uses around 500W of power.
Abundance of fresh water enables owners to run devices like washing machines without much need to stop and resupply. (Pictured above: washing machine on a Pegasus 50)
Making use of surplus power
On yachts with large battery banks and ample renewable generation, such as extensive solar arrays and hydrogenerators, there are often periods when surplus power would otherwise be wasted. This might be on sunny afternoons, once the batteries are fully charged, or when sailing fast with a hydrogenerator deployed. Running the watermaker at these times makes productive use of energy that would otherwise be lost.
Maintenance
Maintenance is another common worry, but the reality is that little is required, especially for units that are used on a regular basis. Generally the advice to prevent bacteria developing in the membrane is that watermakers should be run at least once every seven days in temperate regions and every three days in the tropics.
Used this way the only routine maintenance is replacing the pre-filter, a cheap service item, after every 4-5 tonnes of water has been produced. Watermakers are best used away from the contaminated waters of harbours and estuaries, but if remaining in port for any length of time then a freshwater flush, or pickling the unit, is only a five minute task and the boat can then be left for months.
Pictured above: seawater intake on the Pegasus 50, including the watermaker. Having everything pre-installed and labeled increases reliability of the system and ease of maintanance.
Membranes
Membranes are more expensive, but replacing them is also a straightforward operation. They typically last for more than six years and usually only need to be replaced when water quality falls and/or working pressure rises, despite chemical cleaning.
Installation
The installation is an important factor that's often overlooked or even compromised, especially when systems are retrofitted. Common problems include placing the water intake where there's a risk of it drawing in air bubbles, while inadequate battery charging arrangements can also create issues.
Watermakers as standard on Pegasus yachts
Watermakers are standard equipment for all Pegasus models, which allows the installation and power requirements to be designed and engineered from the outset as fully integrated elements of the boat's systems. Both models use efficient low voltage Schenker watermakers, which draw little more than 10A of power on 24V systems. The Pegasus 50 is equipped with the 50 L per hour model, while the Pegasus 67 is equipped with Schenker 100, providing 100 L per hour output and has the added benefit of redundancy.
