A seawater desalination device converts raw salt water into fresh drinking water using reverse osmosis. If you are choosing one for a boat, catamaran, camper or remote property, the core question is not which brand looks best, but which output, power source and form factor actually matches how you use water at sea or off-grid. This guide walks through exactly that, using the LEDI range as concrete, real-world examples.
What a Seawater Desalination Device Actually Does
Every reverse osmosis watermaker pushes raw water through a semi-permeable membrane at high pressure. The membrane rejects dissolved salts, bacteria and most contaminants, passing clean permeate into your tank and sending concentrated brine back overboard. The LEDI Scout, for example, achieves 99.4% salt rejection, producing water typically in the range of 250 to 300 ppm TDS from seawater up to 35,000 ppm. That output meets Australian drinking-water standards. A built-in UV steriliser adds a second treatment stage after the membrane.
The technology itself is mature and well-understood. What varies between units is output rate, power draw, portability, and how much installation is involved. Getting those four things right for your situation is what this guide is about.
Portable 12V vs Fixed Installed Systems
Traditional installed watermakers are wired in below deck, plumbed into a seacock, and require a professional refit. They can cost $10,000 to $25,000 fully installed. A portable seawater desalination device like the LEDI Scout sidesteps all of that. You drop a submersible feed pump over the side, connect the supplied hoses, plug into a 12V source, and you are making water in minutes. No plumbing, no boatyard, no generator required.
That portability comes with real advantages for most recreational sailors and cruisers. The Scout weighs 18 kg and can be moved between boats, taken on a 4WD trip, or stored ashore between seasons. The trade-off is lower output, 10 or 20 litres per hour, which suits a crew of two to four on passages up to several weeks. If your daily demand is higher, a higher-output unit is the better fit.
For a detailed side-by-side breakdown of portable versus installed systems, see the article Portable vs Installed Watermaker.
How to Match Output to Your Actual Water Use
Before comparing devices, work out your daily litres. A rough guide for a boat:
- Drinking and cooking: roughly 2 to 3 litres per person per day at a minimum, 5 to 6 litres more comfortably
- Washing up: 5 to 15 litres per day for a crew of two to four
- Showers underway: adds 10 to 30 litres per day depending on habit
- Safety buffer for windless days or equipment downtime: 20 to 30% on top
A couple on a 35-foot cruiser doing easy passages might need 30 to 40 litres a day. Running a LEDI Scout 20 LPH for two to three hours fills that requirement comfortably on a normal 12V house bank with 200 to 400 watts of solar. A bigger crew, liveaboards, or charter use with daily showers might need 80 to 120 litres a day, which points toward the Nomad.
For a more detailed sizing exercise, see How to Size a Watermaker System Properly.
The LEDI Scout: A Practical Portable Desalination Device
The LEDI Scout is available in 10 LPH and 20 LPH versions, priced from $4,899 AUD. It runs on 12V DC, drawing 16 to 18 amps, which a standard house battery bank handles without a generator. The high-pressure pump is a Pumptec 107SS built in the USA from 316 stainless steel, rated to around 800 PSI. Pre-filtration is a 5-micron cartridge that is a cheap, quick swap when feed pressure rises or output drops.
Key practical details:
- Supplied with a submersible feed pump, drop it over the side or connect to a seacock
- Standard 5 m feed hose included; the Scout Auxiliary Feed Pump or the Nomad Auxiliary Feed Pump extends reach for longer runs, up to roughly 20 to 30 m horizontally
- Built-in UV steriliser and internal hour meter for servicing
- 18 kg, single-person carry
- Handles seawater up to 35,000 ppm as well as brackish and river water
- Noise around 65 dB, similar to a dishwasher
The Scout suits trailer sailers and cruising yachts from 20 to 50 feet, catamarans, campers and 4WD setups where space is limited and installation is not practical.
The LEDI Nomad: High-Output Desalination for Bigger Demands
The LEDI Nomad produces 40, 60 or 80 litres per hour and runs on 12V or 24V DC, with a 240V mains adapter available. It features a Cat Pumps 2SFSEEL 316-stainless high-pressure pump, an integrated control panel with TDS monitor and flow meter as standard, a two-stage pre-filtration system, 316 stainless DEFLOK fittings, and an internal hour meter. It is autoflush-compatible and weighs around 38 to 42 kg.
The Nomad is priced at $9,899 AUD for the single-membrane configuration and $10,899 AUD for double-membrane. It suits liveaboards, larger crews, charter boats, long blue-water passages, or anyone who wants to run showers underway without anxiety about the water supply.
Parts, Maintenance and Ongoing Costs
Both LEDI units use non-proprietary, off-the-shelf parts that are available and serviceable anywhere in the world. That matters on a long passage far from a Gold Coast boatyard.
Routine maintenance involves:
- Pre-filter cartridge replacement every 10 to 40 hours depending on water clarity; the 2.5 x 5 inch Scout pre-filter cartridge costs $25 AUD
- Freshwater flush after each use to protect the membrane
- Membrane pickling for storage periods longer than a few weeks
- Pump service kit for the Pumptec at intervals; the Pumptec Service Kit A is $248 AUD
The RO membrane is not a regular consumable. With proper flushing and pickling it lasts several years. A replacement Seawater RO Membrane is $330 AUD if you eventually need one. All spare parts are available through the LEDI spares store, posted Australia-wide and internationally, usually within one business day.
LEDI offers a one-year warranty, extended to two years on registration, plus lifetime in-house servicing on the Gold Coast.
Why Australian-Made Matters for a Desalination Device
LEDI builds every unit on the Gold Coast. There is no importer, no overseas distributor, and no freight markup on a heavy commercial unit. You deal with a real person when you call or email, not a call centre. That also means the team can answer specific questions about your boat, your power setup and your cruising plans before you commit.
The parts inside, the Pumptec pump, the Cat pump, the membranes, the fittings, are the same commercial marine-grade components used in fixed installed watermakers costing two to four times as much. The difference is the form factor and the absence of installation labour.
LEDI ships worldwide. Freight is calculated at checkout for Australian orders; for international shipping, contact the team at info@ledi.com.au or on +61 494 562 668 for a freight quote. Import duties and taxes are the responsibility of the buyer in the destination country.
Frequently Asked Questions
Can I run a seawater desalination device off solar alone?
Yes. The Scout draws 16 to 18 amps at 12V. A standard 200 to 400-watt solar setup paired with a house battery bank handles it without a generator. You do not need to run the engine or carry extra fuel just to make water.
How long does the RO membrane last?
Several years with correct care, meaning a freshwater flush after each use and membrane pickling for any storage period. The membrane is not a routine consumable. If output drops significantly or water quality falls off, the team can help diagnose whether the membrane is the cause before you replace it.
Does the Scout work with brackish or river water, or only seawater?
The Scout handles seawater up to 35,000 ppm as well as brackish and river water. Lower-salinity feed water is actually easier on the membrane and the pump, so output and membrane life are generally better in brackish conditions.
What is included when I buy a LEDI watermaker?
The Scout ships with the unit, a submersible feed pump, all hoses and fittings, and instructions. The Nomad includes the unit with integrated panel, TDS monitor, flow meter, two-stage pre-filtration, hoses, fittings and instructions. The Watermaker Install Kit is available separately if you want additional fittings for a semi-permanent setup.
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