Watermakers in Australia

What a watermaker does and when you need one

A watermaker produces potable water from seawater by forcing the seawater through semi‑permeable membranes that reject salt and most contaminants. The unit includes prefiltration to remove solids and protect the membranes, a high‑pressure pump that creates the necessary pressure for reverse osmosis, and controls for flow, pressure and flushing.

You need a watermaker when you want to reduce dependence on shore water, carry less heavy stored water, or cruise remote coasts for extended periods. Owners of liveaboard boats, long‑distance cruisers, charter operators and commercial vessels commonly fit watermakers. Even infrequent cruisers find them useful in regions where potable water is costly or inconsistent.

What a good job looks like

A competent installation or service will deliver steady production at the system’s rated output, low salt content in the product water (verified by a conductivity or TDS test), no leaks, correct operation of pressure and safety devices, and easy access for routine maintenance. Technicians should leave clear notes about any replaced parts, membrane condition and recommendations for continued operation.

Indicators of quality work include:

• Measured freshwater conductivity/TDS before and after service
• Confirmation of correct feed and product pressures
• Clean, secure raw‑water intake and functioning strainers
• Properly fitted high‑pressure plumbing with quality fittings and clamps
• Clear labelling of valves and drainage for flushing procedures

What installation involves

Installation typically includes selecting an appropriate location (engine room, lazarette or dedicated locker), mounting the unit, plumbing raw‑water pickup (through‑hull or sea chest), installing prefilters and membranes, routing product water into the freshwater tank and integrating electrical power. Electrical work often needs a marine electrician because of AC/DC conversion, inverters or generator interfaces and battery loads.

Other installation tasks include fitting a seawater strainer, setting up an automated flush or manual flush system, and planning service access so prefiltres and membranes can be changed without lifting heavy gear.

Routine servicing and repairs — what to expect

A standard service visit will usually cover inspection, prefilter changes, membrane flush and performance testing. The technician should record production litres per hour, feed pressure, brine flow and product water conductivity. If membranes are degraded, they may recommend cleaning or replacement — membrane lifespan varies with use, feedwater and maintenance. Repairs commonly involve replacing seals, impellers, valves, hose clamps, sensors or repairing the high‑pressure pump.

Good service practice also includes advising on anti‑fouling and stabilising procedures for seasonal layup, and safe disposal of cleaning chemicals or spent filters in line with local environmental requirements.

What to ask and check before you book

Before you call a watermaker technician, gather basic information and be ready to answer these questions to speed up diagnosis and give the technician what they need:

• What is the watermaker make, model and serial number? (If known.)
• Where is it installed on the boat and how easy is access to filters and membranes?
• How old are the membranes and when were they last serviced or flushed?
• What power is available on board (battery bank capacity, inverter size, generator)?
• Is the raw‑water intake via through‑hull, sea chest or external pickup?
• Describe the problem: low production, salty product water, leaks, unusual noises, or electrical faults.
• When did you last replace prefilters and change feed‑water strainer baskets?

Also ask the service provider what tests they will perform and whether they will provide a written report with production numbers, TDS/conductivity readings and recommendations. Ask how they handle chemical cleaning and disposal, whether they will need a shore power hookup or to run your generator, and whether any haul‑out or hull work is likely.

Practical tips and Australian conditions

Tropical and temperate Australian waters can cause rapid fouling — if you cruise the Great Barrier Reef, Kimberley or northern coast, insist on regular inspections and consider a scheduled monthly flush during extended stays. In turbid harbour or river mouths where sediment is high, replace prefilters more often. Never run a watermaker on poor‑quality feedwater without additional prefiltration.

Finally, plan for routine checks: keep spare prefilter elements, an approved cleaning kit and a calibrated conductivity/TDS meter aboard. A well‑installed and serviced watermaker gives confidence offshore; a neglected one can stop producing when you need it most. Ask the right questions before you book and expect clear test numbers and maintenance records after every service.