A seawater desalination system takes raw ocean, brackish or river water and pushes it through a reverse osmosis membrane at high pressure, stripping out salt and other dissolved solids to leave clean, drinkable fresh water. The core technology is the same whether you spend $5,000 or $50,000, but the portability, output, power draw and price vary enormously. This guide covers how the systems work, what really differentiates them, and which LEDI unit makes sense for different situations.
How a Seawater Desalination System Actually Works
Every reverse osmosis desalination system shares the same basic flow: raw water is pumped through a pre-filter to remove sediment, then a high-pressure pump drives it against a semi-permeable RO membrane. Water molecules pass through; dissolved salts and most contaminants are rejected and flushed overboard as brine. The permeate (product water) that comes through the membrane is then passed through a UV steriliser before it reaches your tank.
The key number is salt rejection. LEDI's Scout and Nomad units achieve 99.4% salt rejection, producing output water typically in the 250 to 300 ppm TDS range, well under the 800 ppm upper limit and comfortably within Australian drinking-water standards. Feed water can be full ocean seawater up to 35,000 ppm, or lower-salinity brackish and river water.
Portable vs Fixed: Why Portability Changes Everything
Traditional fixed watermakers are plumbed permanently below deck, require professional installation, and cost $10,000 to $25,000 installed. A portable seawater desalination system like the LEDI Scout does the same job with the same commercial-grade membrane and pump, but needs no installation whatsoever. Drop the stainless intake over the side, connect the supplied hoses and you are making water within minutes.
The practical advantages are real:
- Move it between boats, a 4WD, a campsite or a catamaran without any plumbing work.
- No through-hull penetrations to worry about, maintain or insure.
- If something fails on a fixed unit mid-passage, you may be stuck. A portable unit can be lifted out, inspected, and every part is field-replaceable.
- Lower purchase price because LEDI manufactures on the Gold Coast rather than importing a branded European box with distributor markups.
The LEDI Scout: A 12V Seawater Desalination System from $4,899
The LEDI Scout is a self-contained 12V DC seawater desalination system producing 10 or 20 litres per hour. It weighs 18 kg, so one person can carry and stow it. Power draw is 16 to 18 A at 12V, which a standard house battery backed by 200 to 400W of solar handles comfortably, no generator needed.
Inside the Scout is a Pumptec 107SS high-pressure pump (made in the USA, 316 stainless, roughly 800 PSI), a 5-micron pre-filter, a marine-grade RO membrane and a built-in UV steriliser. An internal hour meter tracks running hours so you know when servicing is due. The Scout ships with a submersible feed pump that sits in the water and plugs in directly.
For most trailer sailers, cruising yachts from 20 to 50 feet, catamarans and campers, the 20 LPH Scout is the straightforward answer. Pricing is $4,899 AUD for the 10 LPH and $5,799 AUD for the 20 LPH. Parts are non-proprietary and available from LEDI's spares store, usually dispatched within one business day.
The LEDI Nomad: High-Output Desalination for Bigger Needs
Where daily water demand is higher, such as a liveaboard couple, a larger cruising crew, a charter yacht or a boat with showers running underway, the LEDI Nomad is the better fit. It produces 40, 60 or 80 LPH and runs on 12V, 24V or 240V (via mains adapter). The Nomad uses a Cat Pumps 2SFSEEL 316-stainless plunger pump, a two-stage pre-filtration system, an integrated control panel with TDS monitor and flow meter as standard, and 316 stainless DEFLOK fittings throughout.
The Nomad is available to order now at $9,899 AUD for the single-membrane configuration and $10,899 AUD for the double-membrane. At roughly 38 to 42 kg it is heavier than the Scout but still portable enough to stow in a deck locker between passages.
The Modular Option: When You Want It Out of Sight
If you are doing a refit or building a new vessel and want the desalination system installed permanently below deck, the LEDI Modular kit is designed for exactly that. It is configurable from roughly 10 to 80-plus LPH, includes a remote control panel and is compatible with auto freshwater flush. Pricing depends on configuration, so contact the LEDI team for a quote.
What Determines the Right System for You
Matching the right seawater desalination system to your situation comes down to four things:
- Daily water demand. A couple on a 35-foot cruiser typically needs 10 to 20 litres per day for drinking and cooking. The Scout 20 LPH handles that in one to two hours. A liveaboard family wanting showers, laundry and cooking water may need 60 to 100 litres per day, which pushes toward the Nomad.
- Available power. The Scout runs happily on 12V solar. The Nomad offers 12V, 24V and 240V options. Neither requires a generator.
- Installation preference. No installation at all, the Scout. Occasional use stored in a locker, the Nomad. Permanent below-deck install, the Modular.
- Budget. The Scout starts from $4,899 AUD. The Nomad from $9,899 AUD. Every system uses non-proprietary parts that are cheap to replace anywhere in the world.
If you are unsure which output suits your trip, the article How Much Water Does a Watermaker Produce? works through daily consumption in more detail, and How to Size a Watermaker System Properly covers the full sizing methodology.
Maintenance: Less Than You Probably Expect
The routine consumable on a seawater desalination system is the pre-filter cartridge, not the membrane. On the Scout, the standard 5-micron 2.5"x5" cartridge costs $25 and needs replacing roughly every 30 to 40 hours in clean ocean water, or 10 to 20 hours in silty or brackish conditions. An optional 2.5"x10" cartridge (also available in the Watermaker Install Kit) holds more dirt and extends the interval between changes.
The RO membrane is not a regular consumable. With proper care, specifically a freshwater flush after every use and membrane pickling for storage, a membrane lasts several years. The UV steriliser, pre-filter housing and all fittings are standard, off-the-shelf parts that can be sourced and replaced anywhere. LEDI also provides lifetime in-house servicing on the Gold Coast for every unit it builds.
Frequently Asked Questions
How much does a seawater desalination system cost in Australia?
The LEDI Scout starts at $4,899 AUD for the 10 LPH model and $5,799 AUD for the 20 LPH model. The Nomad starts at $9,899 AUD. Both are hand-built to order on the Gold Coast. Australian shipping is calculated at checkout; international freight is quoted on request. See the full pricing breakdown in the article Seawater Desalination Cost: What to Budget in 2026.
Can a portable desalination system run on solar power alone?
Yes. The Scout draws 16 to 18 A at 12V DC. A standard house battery bank with 200 to 400W of solar panels is enough to run it comfortably without a generator. The Nomad is also available in 12V and 24V configurations suited to solar setups.
What water sources can these systems handle?
Both the Scout and the Nomad are rated for full ocean seawater up to 35,000 ppm TDS, as well as brackish water and river water. Feed water should be free of oils, fuel and heavy chemical contamination. The pre-filter handles sediment; the RO membrane handles dissolved salts.
Is a portable watermaker safe for drinking water?
LEDI units treat water by reverse osmosis and UV sterilisation, and the output typically reads 250 to 300 ppm TDS, which meets Australian drinking-water standards. The units do not hold any formal certification such as CE marking. If you have a specific regulatory requirement, contact the LEDI team to discuss.
Ready to work out which seawater desalination system suits your boat or trip? Contact the LEDI team directly at info@ledi.com.au or call +61 494 562 668. You will speak with a real person, not a call centre.
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