A catamaran is one of the best platforms for carrying a watermaker: plenty of deck space, good solar real estate, and the kind of passage-making range that makes water independence genuinely useful. The question is which system fits your boat, your crew size, and the way you actually sail. This guide covers the key decisions so you can match the right unit to your needs without overbuying or undershooting.
How much output does a catamaran crew actually need?
A practical rule of thumb is 5 to 8 litres of drinking and cooking water per person per day when you are conserving, or up to 15 litres per person if you include washing up. Add showers and the numbers climb fast.
- Two people, day sails and short passages: 10 to 20 litres per day. A 10 LPH unit running for one to two hours covers this comfortably.
- Two to four people, extended cruising: 30 to 60 litres per day. A 20 LPH unit running a couple of hours handles it; a 40 LPH unit halves your run time.
- Four to six people or liveaboard use with showers: 80 to 120 litres per day. You need a high-output system in the 60 to 80 LPH range.
These figures help you avoid the common mistake of buying output you never use, or buying too little and running the unit for hours every single day to catch up.
Portable vs permanently installed: what suits a catamaran?
Catamarans often have locker space that smaller monohulls do not, which makes a permanent install viable. But a portable unit has real advantages even on a cat. You do not lose locker space to plumbing. You can move the unit between hulls or onto the dock. If you sell the boat, the watermaker comes with you. And if something needs servicing, you carry the whole unit ashore rather than working in a confined bilge.
A permanently installed modular system makes sense when you want the unit truly out of sight, connected to your boat's tanks automatically, with a remote control panel at the helm or nav station. The LEDI Modular kit is designed for exactly this: a configurable below-deck install with auto freshwater flush and remote panel, suited to refits and new builds. Pricing depends on configuration, so contact the LEDI team for a quote.
For most cruising catamarans up to around 50 feet, a portable unit that stows in a locker and deploys in minutes is often the more practical and more affordable choice.
Which LEDI unit matches your catamaran?
LEDI makes three systems, and the right one depends on your output needs and whether you want a portable or installed setup.
LEDI Scout (10 or 20 LPH): The LEDI Scout watermaker is a fully self-contained portable unit. Drop the stainless intake over the side, connect the supplied hoses, and you are making water in minutes. No plumbing, no installation. At 18 kg it is a single-person carry. The Pumptec 107SS pump runs at around 800 PSI and draws 16 to 18 A from 12V DC, meaning a healthy house bank with 200 to 400 W of solar handles it without a generator. Built-in UV steriliser, 99.4% salt rejection, output typically 250 to 300 ppm TDS. Priced from $4,899 AUD for the 10 LPH and $5,799 AUD for the 20 LPH. Best for couples and small crews on catamarans up to about 50 feet.
LEDI Nomad (40, 60 or 80 LPH): The LEDI Nomad watermaker is built for bigger crews, liveaboards, and heavier daily use. It uses a Cat Pumps 2SFSEEL 316-stainless pump, comes standard with an integrated control panel, TDS monitor and flow meter, and 2-stage pre-filtration. Available in 12V or 24V DC (240V via mains adapter). Weighs around 38 to 42 kg. Priced at $9,899 AUD for the single-membrane unit or $10,899 AUD for double-membrane. Right for larger cats with four or more people, charter use, or anyone who wants showers underway without worrying about tank levels.
LEDI Modular: For a clean, permanent install below deck. Configuration-dependent pricing. Contact LEDI for a quote.
Power and solar on a catamaran
Catamarans are excellent solar platforms. Wide cabin tops and stern arches typically carry 400 to 1,200 W of panels, often feeding large lithium or AGM banks. The Scout's 16 to 18 A draw at 12V (around 200 W) is modest compared to a watermaker with a 240V pump. Running the Scout for two hours while the sun is up costs roughly 400 Wh, which most cruising cats recoup in an hour of good solar.
The Nomad's 12V or 24V DC options also keep it generator-free on a well-set-up cat. If you are already running a 24V system, the Nomad's 24V option is the cleaner choice. For 240V use, the optional mains adapter lets you run it from a shore power connection or generator when you need maximum run-time flexibility.
Whatever your setup, check your actual battery capacity and solar harvest before sizing up. The guide to running a watermaker on battery power walks through the numbers in plain terms.
Saltwater, silty anchorages and pre-filtration
Catamarans anchor in some spectacular but sometimes murky spots, from mangrove-fringed bays to Pacific atolls with stirred-up sand. Pre-filtration is what protects the RO membrane from that dirt. The Scout comes with a 5-micron 2.5" x 5" cartridge filter as standard. In clean ocean water you will get 30 to 40 hours between changes; in silty or dirty water, closer to 10 to 20 hours. The cartridge itself costs $25 and takes minutes to swap.
If you regularly anchor in murky conditions, the larger 2.5" x 10" pre-filter housing extends the time between changes and gives the membrane cleaner feed water. It is included in the Watermaker Install Kit or available as a standalone add-on. The Nomad comes with 2-stage pre-filtration as standard.
After every use, flush the membrane with fresh water. For storage over a few weeks, pickle it. These two habits are the biggest factors in membrane longevity. The article on watermaker membrane lifespan explains exactly what damages membranes and how to avoid it.
Why Australian-made matters for parts and service
Both the Scout and Nomad use non-proprietary, commercially available parts. The Scout's Pumptec 107SS pump and the Nomad's Cat Pumps unit are both fully serviceable. Spare parts ship from the Gold Coast to anywhere in Australia, usually within one business day. LEDI offers lifetime in-house servicing and a 1-year warranty (2 years when registered). You are not locked into an overseas manufacturer's service network.
Being built in Australia rather than imported also keeps costs down. Fixed below-deck watermakers with similar output and equivalent components often run $10,000 to $25,000 installed. A portable LEDI system using the same commercial-grade parts starts at $4,899. Browse spare parts and accessories to get a feel for ongoing costs.
Frequently asked questions
Can I use a portable watermaker on a catamaran without any plumbing?
Yes. The LEDI Scout is designed to need no installation at all. Drop the stainless intake filter over the side, connect the supplied hoses, and run the output into a tank or jerry can. The unit stows in a locker between uses. If you later want a permanent plumbed-in setup, the LEDI Modular kit is the right path.
What output do I need for a catamaran with four people?
Four people using around 10 to 15 litres each per day need 40 to 60 litres daily. A 20 LPH Scout running three hours covers the lower end; the 40 LPH Nomad covers it in about an hour. For liveaboards wanting showers, move to the 60 or 80 LPH Nomad. See the guide to watermaker output for a fuller breakdown.
Will a 12V watermaker run on a catamaran's solar system?
In most cases, yes. The Scout draws around 200 W at 12V. A cruising cat with 400 W or more of solar and a reasonable battery bank runs it easily during daylight hours without touching generator fuel. The Nomad's 12V or 24V DC options are similarly solar-compatible on a well-set-up boat.
How do I decide between the Scout and the Nomad for my catamaran?
If you are a couple or small crew doing passages and coastal cruising, the Scout 20 LPH at $5,799 covers you comfortably. If you have four or more people, use a lot of water for showers, or run the boat as a charter, the Nomad's higher output justifies the extra cost. If you are unsure, contact the LEDI team directly at info@ledi.com.au or call +61 494 562 668 and talk it through with a real person.
Ready to sort your catamaran's water independence? View the LEDI Scout and the LEDI Nomad for full specs and current pricing, or get in touch with the team at lediwatermaker.com.
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