A watermaker for a motor yacht is one of the most practical investments you can make before a serious passage. It frees you from marina top-ups, lets you anchor where you want, and removes the mental load of rationing water for a crew. The right system depends on your output needs, how you manage power, whether you want a portable unit or a permanent install, and how many people are aboard.
How much water does a motor yacht actually need?
Most coastal cruisers on a motor yacht use between 20 and 60 litres of fresh water per person per day, depending on whether they shower aboard. A weekend couple doing bay hopping might need 40 to 80 litres a day total. A larger crew running extended passages or a charter operation can easily burn through 120 to 200 litres a day once showers, cooking and washing up are counted.
Getting that number right before you choose a watermaker saves you from either under-speccing and running the unit constantly, or over-speccing and paying for capacity you never use. The guide How Much Water Do You Actually Need? walks through a simple daily-use calculation worth doing before you buy.
Portable versus installed watermaker on a motor yacht
Motor yachts have more usable space than most sailboats, but that does not automatically mean a permanent below-deck install is the right choice. Portable systems offer real advantages, particularly for owners who also trailer the boat, lend it out, or want a system that can be moved between vessels.
- Portable: No installation, no through-hulls, no plumbing work. Drop the intake over the side, connect the hoses, and you are making water in minutes. Suits owners who want flexibility or do not want a yard job before departure.
- Semi-permanent or below-deck modular: Tidier, out of the way, and can be set up with a remote panel and auto freshwater flush. Worth considering if the boat is your home or primary cruising vessel and you want a fitted finish.
The Portable vs Installed Watermaker article covers this trade-off in more detail if you are weighing up the options.
The LEDI Scout: best portable watermaker for smaller motor yachts
The LEDI Scout is a 12V portable reverse osmosis watermaker built on the Gold Coast. It produces 10 or 20 litres per hour, weighs 18 kg and is carried by one person. There is no installation. A submersible feed pump drops over the side, you connect the supplied hoses, and within minutes you have fresh water running.
For a motor yacht with a couple aboard doing coastal or offshore passages, the 20 LPH Scout run for two to three hours a day typically covers daily drinking, cooking and some washing up. Key specs that matter on a motor yacht:
- 12V DC, 16 to 18 A draw. Runs directly off your house bank. Compatible with 200 to 400 W of solar, so no generator required.
- 99.4% salt rejection. Output is typically 250 to 300 ppm TDS, well under the 800 ppm threshold for safe drinking water. Built-in UV sterilisation. Meets Australian drinking water standards.
- Handles seawater up to 35,000 ppm, plus brackish water or river water. The Pumptec 107SS high-pressure pump (USA-made, 316 stainless) operates at around 800 PSI.
- Internal hour meter tracks running hours, making service intervals straightforward.
- 5 m standard feed hose. For longer runs, the Scout Auxiliary Feed Pump or the Nomad Auxiliary Feed Pump handles distances up to roughly 20 to 30 m horizontally and up to 5 m of vertical lift. Both use the same SP13 2-pin connector and plug straight in.
- Priced from $4,899 AUD.
The LEDI Nomad: for larger motor yachts and bigger crews
If your daily water demand is above what a Scout can cover comfortably, or you have a larger motor yacht with a bigger crew, the LEDI Nomad is the next step up. It produces 40, 60 or 80 litres per hour, runs on 12V or 24V DC, and includes an integrated control panel with a TDS monitor and flow meter as standard.
The Nomad uses a Cat Pumps 2SFSEEL 316-stainless high-pressure pump, 2-stage pre-filtration, DEFLOK 316 stainless fittings, and an internal hour meter. It is autoflush-compatible. At roughly 38 to 42 kg, it is a two-person lift, but it remains portable in the sense that it does not require a permanent install if you do not want one.
For a motor yacht with a crew of four or more, a charter operation, or a liveaboard where hot showers underway are part of daily life, the Nomad 40 or 60 is almost always the right fit. The Nomad is available to order now: single-membrane from $9,899 AUD, double-membrane from $10,899 AUD.
What about a below-deck modular install?
Motor yachts with a dedicated engine room or bilge space, or new builds being fitted out from scratch, are good candidates for the LEDI Modular system. This is a configurable kit designed for permanent or semi-permanent installation, with output from around 10 to 80-plus LPH depending on configuration, a remote control panel, and auto freshwater flush. Pricing depends on configuration. Contact the team for a quote if a modular install suits your build.
Power and solar on a motor yacht
Motor yachts typically have more charging capacity than sailboats, between the main engines, a generator and shore power. That said, running the Scout off your 12V house bank with solar is straightforward and common. A standard house battery plus 200 to 400 W of solar handles the Scout's 16 to 18 A draw comfortably without needing to fire up the main engines or a genset just to make water.
The Nomad's higher output means a higher current draw. The team can confirm the right setup for your specific electrical system.
Maintenance: what it takes to keep a motor yacht watermaker running
The routine consumable on any LEDI system is the pre-filter cartridge. On the Scout, this is a 5 micron 2.5 x 5 inch cartridge, replaced roughly every 30 to 40 hours in clean ocean water or every 10 to 20 hours in silty or coastal water. A replacement cartridge costs $25 AUD and takes minutes to swap. The Scout is also compatible with a larger 2.5 x 10 inch pre-filter cartridge for extended intervals between changes.
The RO membrane is not a routine consumable. With a freshwater flush after each use and proper pickling during storage, it lasts several years. Replacement membranes, chemicals and all wear parts are available through the LEDI spares store and post Australia-wide and internationally, usually within one business day.
Every LEDI system comes with a 1-year warranty, extended to 2 years on registration. Lifetime in-house servicing is available on the Gold Coast.
Frequently asked questions
Can I use a portable watermaker on a motor yacht without installing anything?
Yes. The LEDI Scout requires no through-hulls, no plumbing and no installation. You drop the submersible feed pump over the side, connect the supplied hoses to the unit and run a freshwater output line to your tank or direct to a tap. The whole setup takes a few minutes and is fully reversible.
How many litres per hour do I need for a motor yacht with four people aboard?
A crew of four using around 30 litres per person per day needs roughly 120 litres daily. A Scout 20 LPH run for six hours covers that, or a Nomad 40 run for three hours. If showers are part of daily use, a Nomad 40 or 60 is more practical since it delivers the volume faster and with less run time. The team can help you match output to your specific daily use.
Will the LEDI Scout work off my motor yacht's 12V house bank?
Yes. The Scout draws 16 to 18 A at 12V DC and connects directly to a standard house battery. Most motor yachts with a house bank of 100 Ah or more can run it comfortably alongside normal onboard loads, especially if you are motoring and alternators are charging at the same time.
What does the Nomad include as standard?
The Nomad comes with the unit, integrated control panel with TDS monitor and flow meter, 2-stage pre-filtration, hoses and fittings, and instructions. The internal hour meter is installed as standard. Autoflush compatibility is built in. Contact the team at info@ledi.com.au or +61 494 562 668 to confirm the configuration that suits your motor yacht.
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