A watermaker is a reverse osmosis (RO) system that forces raw water through a semi-permeable membrane at high pressure, stripping out salt, bacteria, and dissolved solids to produce clean drinking water. If you spend serious time offshore, on a remote property, or deep in the Australian bush, a watermaker is one of the most practical investments you can make. This guide walks you through how they work, what specifications actually matter, how to choose the right system, and what it costs to own one in Australia.
How a Watermaker Works
Every watermaker follows the same basic process:
- Pre-filtration: Raw water passes through a sediment filter to remove particles that would damage the membrane.
- High-pressure pump: A pump raises water pressure to between 600 and 1000 PSI, depending on source water salinity.
- RO membrane: At high pressure, water molecules are forced through the membrane. Dissolved salts, bacteria, and other contaminants are rejected and flushed away as brine.
- Product water output: Clean, low-TDS water flows to your tank or directly to a tap.
The quality of each component determines how reliable, long-lasting, and efficient the whole system is. For a deeper look at the science, read Inside a Modern Watermaker: The Simple Science Behind Turning Seawater Into Safe Drinking Water.
What Output Do You Actually Need?
Before comparing systems, work out your daily water demand. Most sailors and liveaboards need between 10 and 30 litres per person per day when you account for drinking, cooking, and basic hygiene. A family of four on an extended passage needs at least 60 litres per day from a single session of one to two hours of running time.
The LEDI Scout 12V Watermaker, priced at $4,899 AUD, is rated for marine, boating, camping, and sailing. It runs directly from a 12V battery bank or solar setup and is designed to cover the water needs of small to medium crews without burdening your electrical system. If you need significantly higher output, the LEDI Nomad Watermaker at $8,299 AUD is the heavier-duty option suited to larger vessels and off-grid properties with AC power available.
For a practical breakdown of how output ratings translate to real-world use, see How Much Water Can You Really Make at Sea? Output Ratings vs Real-World Performance.
Portable vs Installed Watermakers
Traditional installed watermakers are plumbed permanently into a vessel. They take up locker space, require professional installation, and become a liability if you sell the boat or switch vessels. Portable watermakers work differently. They connect via a hose to your water source and draw power from a 12V outlet or your battery bank, so you can move them between boats, take them on a 4WD trip, or deploy them in an emergency.
The LEDI Scout is built around this portable philosophy. Australian made, it is compact enough to stow in a locker but powerful enough to be your primary fresh water source. If you want to explore a modular self-install approach instead, the LEDI Modular Kit is available at $4,699 AUD for those who prefer a more permanent setup.
For a detailed comparison of these two approaches, see Portable vs Installed Watermaker.
Key Components to Understand Before You Buy
A watermaker is only as good as its weakest component. Here is what to check:
- RO membrane: The heart of the system. The Seawater RO Membrane used in the Scout is a marine-grade seawater membrane, available as a spare for $300 AUD. Membrane life depends heavily on pre-filtration quality and regular flushing.
- Pre-filter: Sediment pre-filters protect the membrane. The 2.5 x 5" cartridge filter that suits the Scout costs $25 AUD and should be replaced regularly.
- High-pressure pump: The pump determines flow rate and reliability. LEDI uses the PUMPTEC 107SS 12V pump, available as a spare at $1,550 AUD, a proven marine-grade unit.
- Feed pump: A low-pressure feed pump draws raw water into the system before the HP pump. The LEDI Scout Auxiliary Feed Pump is available at $229 AUD for installations where gravity feed is not enough.
- Pressure gauge: Monitoring operating pressure tells you immediately if something is wrong. A Stainless Steel Pressure Gauge is $59 AUD and a small but important diagnostic tool.
- TDS monitoring: Know your output water quality in real time. The Inline TDS Sensor is $75 AUD and shows you exactly how well your membrane is performing.
Maintenance: What It Takes to Keep a Watermaker Running
A watermaker requires routine attention. Neglect it and you will shorten the life of the membrane and risk contaminated output water. The main tasks are:
- Flushing: After each use in seawater, flush the system with fresh water to prevent salt crystallisation inside the membrane. Read our full guide: Watermaker Flushing: How Often, Why It Matters, and the Fastest Way to Do It Right.
- Pre-filter replacement: Check and replace pre-filters based on operating hours and source water quality. Replacement cartridges are inexpensive at $20 to $25 AUD.
- Pickling: If the system is going into storage for more than a few weeks, pickle the membrane with a preservation solution. Maintenance Chemicals are available at $12 AUD.
- Membrane inspection: A rising TDS reading from your inline sensor is the first sign a membrane is degrading. Knowing how to manage membrane life saves money over the long run. See Watermaker Membrane Lifespan: What Shortens It and How to Make Yours Last for Years.
All spare parts and consumables are stocked in Australia. Browse the full range at the LEDI Spares collection.
Is Watermaker Water Safe to Drink?
Yes, when the system is operating correctly and maintained properly, RO water from a watermaker is very safe. The membrane rejects over 99% of dissolved salts and the vast majority of bacteria and viruses. For additional peace of mind, especially in tropical waters or areas with algal blooms, adding a UV steriliser to the output line is worthwhile. The 4LPM LED UV Steriliser is available at $420 AUD and is a good add-on for anyone heading to the Pacific Islands or remote coastal areas. For more detail on water safety from RO systems, see Is Watermaker Water Safe to Drink?
What Does a Watermaker Cost in Australia?
The purchase price is only part of the picture. Here is a realistic summary of costs:
- LEDI Scout 12V Watermaker: $4,899 AUD
- LEDI Nomad Watermaker: $8,299 AUD
- Modular Kit (self-install): $4,699 AUD
- Watermaker Install Kit: $180 AUD (for those running the modular setup)
- Annual consumables (pre-filters, chemicals): roughly $50 to $100 AUD per year under normal use
- Membrane replacement: $300 AUD, typically required every three to five years depending on use and maintenance
Compared to buying bottled water or paying marina prices for fresh water on a long passage, the system pays for itself relatively quickly. For a full breakdown, read The True Cost of Owning and Maintaining a LEDI Scout Watermaker.
Ready to Choose Your Watermaker?
If you are looking for a practical, reliable watermaker that is designed and built in Australia, runs on 12V, and goes wherever you do, the LEDI Scout is the straightforward starting point. For larger vessels or higher-output requirements, the LEDI Nomad covers that ground. And if you already have a system and need parts, the LEDI Spares collection has everything from membranes and pre-filters to fittings and gauges, all stocked in Australia and ready to ship.
Have a question about which system suits your setup? Get in touch with the LEDI team directly through the website and get a straight answer, not a sales pitch.
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