A watermaker is one of the most important pieces of kit you can carry on a blue water passage. Once you leave coastal waters, you cannot rely on topped-up tanks, marina taps or shoreside jerry cans. A good system gives you safe drinking water wherever you anchor, however long you stay, without rationing or planning your route around water stops.
This guide covers what actually matters when choosing a watermaker for offshore cruising, the output you need for different crew sizes, how to run a system from 12V without a generator, and which LEDI systems suit different passagemaking setups.
How Much Output Do Blue Water Cruisers Actually Need?
A cruising sailor typically uses 3 to 5 litres of drinking and cooking water per person per day at a minimum. Add basic hygiene, washing up and occasional showers and most people budget 8 to 15 litres per person per day at anchor. For a couple on a 35-foot yacht, that is roughly 15 to 30 litres a day. For a crew of four or five on a catamaran, you are looking at 40 to 75 litres a day or more.
The right output depends not just on daily use but on how often you run the watermaker. Most cruisers run their system for a few hours while sailing or at anchor rather than continuously. A 20 LPH unit run for two hours produces 40 litres. A 40 LPH unit run for two hours produces 80 litres. Match your unit to realistic daily sessions, not theoretical continuous output.
The LEDI Scout: Capable Offshore Watermaker for Smaller Crews
The LEDI Scout is a portable 12V reverse osmosis watermaker available in 10 LPH and 20 LPH outputs, starting from $4,899 AUD. It is designed to need no installation: drop the stainless intake over the side, connect the supplied hoses, and you are making water within minutes.
For a couple or small crew on a yacht between 20 and 50 feet, the 20 LPH Scout is a practical choice. Two hours of running produces 40 litres, enough for a generous daily budget on a two-person boat. The unit weighs 18 kg and is carried by one person, which matters when moving it between boat and shore or storing it below decks when not in use.
Key specs for passagemaking:
- 12V DC, 16 to 18A draw, fully solar-compatible (no generator needed)
- 99.4% salt rejection, output typically 250 to 300 ppm TDS
- Built-in UV steriliser, meets Australian drinking-water standards
- Handles full seawater up to 35,000 ppm and brackish water
- Pumptec 107SS stainless pump (USA made), rated to around 800 PSI
- 5 micron pre-filter, compatible with an add-on 2.5x10" pre-filter for extended intervals between filter changes
The LEDI Nomad: Built for Bigger Crews and Longer Passages
If you are cruising with a larger crew, living aboard, running a charter, or simply want a higher daily water budget without long run times, the LEDI Nomad is the right unit. It is available in 40, 60 and 80 LPH outputs, runs on 12V or 24V DC (240V via mains adapter), and includes an integrated control panel with TDS monitor and flow meter as standard.
The Nomad is priced from $9,899 AUD for the single-membrane version and $10,899 AUD for the double-membrane version. It uses a Cat Pumps 2SFSEEL 316 stainless high-pressure pump, 2-stage pre-filtration, and 316 stainless DEFLOK fittings throughout. It is autoflush-compatible, meaning you can automate the freshwater flush after each session.
For a liveaboard couple with regular guests, or a catamaran doing long Pacific passages with four or more on board, the Nomad covers daily needs in a short run time and leaves headroom for showers and cooking without rationing.
Running a Watermaker on 12V Solar While Offshore
One of the most common questions from blue water sailors is whether a 12V watermaker will drain the battery bank. In practice, a modest solar setup handles it comfortably. The Scout draws 16 to 18A at 12V. A house bank with 200 to 400W of solar panel, the kind of setup most cruisers already carry, can run the Scout during daylight hours without drawing down the batteries, particularly while sailing in trade wind conditions.
This matters because it removes the need to run a generator to make water, which most cruisers prefer at anchor. You can also read about whether a watermaker can run on battery power and how to size your solar for the load in more detail.
Reliability and Parts at Sea
When you are in the Pacific or Indian Ocean, getting a replacement part quickly is not optional, it is a safety consideration. LEDI builds the Scout and Nomad with non-proprietary, off-the-shelf components that are available globally. The pre-filter is a standard 5 micron 2.5x5" cartridge, cheap and stocked by chandlers in most cruising regions. The high-pressure pump is a Pumptec 107SS, a serviceable commercial unit. Every wear part is field-replaceable.
LEDI carries a full range of spare parts and accessories including pre-filter cartridges, RO membranes, and Pumptec service kits, and posts to Australian and international addresses, usually within one business day.
On membrane care: the RO membrane is not a routine consumable. With a freshwater flush after each use and proper pickling before any extended storage period, membranes last several years. You can read more about maximising membrane lifespan and the right flushing routine in the LEDI blog.
Portable vs Installed: What Suits Blue Water Sailors?
Fixed installed watermakers have their place, but they require through-hull fittings, dedicated plumbing and an electrician to fit correctly. On a charter boat or a new build this makes sense. For most blue water cruisers, a portable system offers meaningful advantages: no installation, no through-hull, easy to service in the cockpit, and transferable to the next boat.
If you do want a permanent below-deck installation, LEDI also makes a Modular watermaker kit configurable from roughly 10 to 80 LPH, with a remote control panel and auto freshwater flush. It suits refits and new builds where the watermaker needs to be hidden away. Pricing for the Modular is configuration-dependent; contact the LEDI team to discuss your setup.
What to Check Before You Leave on Passage
A watermaker is only useful if it is working when you need it. Before any offshore passage, run through these checks:
- Replace the pre-filter if it has seen 20 or more hours of use, or if feed pressure has climbed or output has dropped
- Confirm the freshwater flush was done after the last use
- Check the membrane pickle if the unit has been stored for more than a month
- Run the unit at anchor before departure and verify output TDS with the built-in monitor or a handheld TDS meter
- Carry at least one spare pre-filter cartridge for passages over a week
The pre-filter is the one consumable that needs regular attention. In clean open ocean water, a 5 micron cartridge lasts 30 to 40 hours. In silty anchorages or coastal water it may need changing every 10 to 20 hours. A clogged pre-filter starves the high-pressure pump and shortens membrane life. It is a cheap, quick swap and worth keeping a spare on board.
Frequently Asked Questions
Which LEDI unit suits a couple on a 40-foot yacht doing Pacific passages?
The LEDI Scout 20 LPH is the right fit for most couples on yachts in the 35 to 50 foot range. Run it for two hours a day to produce 40 litres, enough for generous daily use on a two-person boat, all from your existing 12V system and solar.
Can the LEDI Scout handle rough ocean water with sediment?
Yes. The Scout includes a 5 micron pre-filter that protects the membrane from sediment and particulates. In silty conditions you may need to change the pre-filter more frequently, roughly every 10 to 20 hours, but the membrane and pump are protected throughout. A larger 2.5x10" add-on pre-filter housing is also available to extend the time between cartridge changes.
What happens if the watermaker needs servicing mid-passage?
Every wear part on the Scout and Nomad is field-replaceable and uses non-proprietary components stocked globally. LEDI also posts spare parts to international addresses from the Gold Coast, usually within one business day. The Pumptec service kit, pre-filter cartridges and RO membrane are all available through the LEDI spares store.
Does a portable watermaker need to be installed to work?
No. The Scout requires no installation at all. You drop the stainless intake filter over the side, connect the supplied hoses to a jerry can or tank inlet, and start making water. There is no through-hull, no plumbing and no electrician needed. The Nomad works the same way. If you want a permanent below-deck setup, the LEDI Modular kit is built for that purpose.
If you are fitting out for a blue water passage and want to talk through which system suits your boat and crew, get in touch with the LEDI team directly at info@ledi.com.au or on +61 494 562 668. You deal with a real person, not a call centre, and they will point you to the right unit without overselling.
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