Watermaker

What is a yacht watermaker?

A watermaker is the system that lets a superyacht produce its own drinking water at sea. Since the 1970s the yacht standard has been reverse osmosis: a high-pressure pump pushes seawater at roughly 55 to 60 bar (800 psi) through a semi-permeable polyamide membrane. Pure water molecules pass through to the potable tank; salt, bacteria, viruses, and dissolved solids are rejected to a brine stream discharged overboard. Older distillation and multi-stage flash technologies are obsolete on modern yachts.

A complete install is more than the membrane. Raw seawater is drawn through a sea-strainer, then 20 µm and 5 µm sediment filters, then a carbon block that protects the membrane from chlorine. After the RO stage, UV sterilisation and, on premium systems, a remineralisation cartridge condition the permeate before it reaches the tank. Modern energy-recovery devices, such as the Spectra Clark pump or Schenker's patented system, recycle pressure from the brine stream to cut power draw by up to 80%.

The category leaders on 40 m-plus yachts include Sea Recovery / HRO, Idromar, Tecnicomar, FCI, and HP Watermaker; the last now offers bridge-integrated systems that move water management out of the engine room and onto the captain's console.

Why it matters for yacht owners

The watermaker is what makes the difference between a yacht that visits remote anchorages and one that genuinely lives in them. In the Tuamotus, Raja Ampat, or the Lofotens there is no dock to plug into; every glass of drinking water, every shower, every jacuzzi top-up is being made onboard from seawater. Range and autonomy, a core capability of a superyacht, are watermaker-dependent.

The economics also tilt onboard. Dockside water in peak-season Mediterranean and Caribbean ports runs €15 to €40 per cubic metre and quality varies; producing your own at roughly 3 to 5 kWh/m³ is normally cheaper and avoids taking on contaminated harbour water. Sustainability is the third axis: a well-specified watermaker, paired with UV sterilisation and remineralisation, eliminates the case-after-case of plastic bottled water that drives single-use waste on charter. For buyers focused on eco-friendly cruising, capacity, energy-recovery design, and post-treatment should be specified at contract or refit stage, not left as an engine-room afterthought.

Key facts

• Reverse osmosis at 55 to 60 bar is the universal yacht standard; older distillation systems are obsolete.
• Salt rejection benchmark: 99.0 to 99.6%, delivering permeate at 200 to 300 ppm TDS, well under the WHO 600 mg/L guideline.
• Capacity span on yachts: 30 L/h on compact units to 3,300+ L/h on superyacht duplex installations.
• Energy with modern pressure-exchanger energy-recovery devices: roughly 3 to 5 kWh per 1,000 litres on marine-scale units (large municipal plants reach ~2.5 kWh/m³); legacy CAT-pump systems without an ERD typically draw two to three times more.
• Typical superyacht freshwater demand: 100 to 150 litres per person per day, with pools and jacuzzis adding periodic top-up.
• Installed cost band: roughly $5,000 for a small DC unit at the entry end, scaling well into the high six figures (in USD or EUR) for fully redundant, dual-train, bridge-integrated superyacht systems on larger hulls. Pricing is bespoke; no published list captures the full range.
• Membrane lifespan: 3 to 7 years typical, 5 to 10 with diligent flushing, pickling, and pre-filter discipline.
• Leading manufacturers: Sea Recovery / HRO, Idromar, Tecnicomar, FCI, HP Watermaker, Spectra, and Schenker.