How do I size a watermaker for my vessel?

Watermaker sizing starts with daily water demand per person on board — typically 15 to 25 gallons per person per day for drinking, cooking, and bathing on a cruising yacht, higher for charter vessels with multiple showers and laundry. Add any washdown or mechanical cooling water requirements on top of that. Then consider how many hours per day the watermaker can realistically run given engine or generator availability. A system should produce your daily requirement in no more than 6 to 8 hours of operation. AMPAC engineers can size the right unit for your vessel from a brief requirements summary.

What happens if I run the watermaker in polluted coastal water?

RO membranes will reject dissolved salts and biological contamination, but they can be chemically damaged or biologically fouled by high-concentration industrial pollutants, petroleum products, and certain organic compounds. Running a watermaker in heavily polluted harbor water or near industrial discharge is not recommended and can permanently damage membranes. Most modern systems include a TDS alarm or conductivity monitoring that detects abnormal permeate quality. The safest practice is to use the watermaker offshore in open water and carry sufficient tankage for coastal passages through potentially contaminated areas.

Do marine watermakers need special maintenance compared to land-based systems?

Marine watermakers require all the same maintenance as land-based RO systems plus a few vessel-specific considerations. Pre-filter replacement schedules remain similar — every 200 to 500 running hours. More critically, when the watermaker will be unused for more than a week, the membrane and pressure vessels should be flushed with fresh water and pickled with a preservative solution to prevent biological growth inside the membrane. Systems left untreated for weeks in warm climates can suffer irreversible biofouling. Always follow the lay-up procedure in the operations manual.

Can AMPAC watermakers run on solar or wind power?

Yes. AMPAC's variable-output marine watermakers can integrate with renewable energy systems. The key is matching the watermaker's power draw to available renewable generation. Smaller 12V or 24V DC watermakers producing 50 to 150 GPD are well-suited for solar/wind systems on cruising sailboats. Larger systems require either a dedicated generator run or a substantial battery bank with inverter. AMPAC can advise on power integration for specific yacht configurations and help spec a system that fits your energy budget.

What is the warranty on AMPAC marine watermakers?

AMPAC SeaPro marine watermakers carry a one-year limited warranty on the complete system and a two-year warranty on membranes under normal operating conditions. Warranty service is available globally through AMPAC's service network and authorized dealers in major boating regions. We maintain a global parts inventory to support vessels in remote locations with minimal downtime. Contact AMPAC USA at (909) 548-4900 or service@ampac1.com to reach our marine service team.

Marine Watermakers | Seawater Desalination

About Ocean & Marine

A vessel's water supply sits entirely outside the municipal grid. Whether the vessel is a superyacht in the Mediterranean, a patrol boat in the South Pacific, or an offshore platform in the North Sea, the only available water source is the sea. When watermaker equipment fails at sea there is no backup supply and no quick service call. The system has to work.

AMPAC USA has been building marine and offshore watermakers since 1993. The SeaPro line covers vessels and platforms from small private yachts needing 100 GPD to military and commercial ships requiring 250,000 GPD or more. All marine systems are built to withstand offshore conditions: saltwater-resistant materials throughout, stainless steel frames and hardware, vibration-tolerant connections, and high-rejection membranes rated for open-ocean seawater at 35,000 to 45,000 ppm TDS.

Watermaker capacity is sized by crew size, charter or passenger capacity, and hotel load including cooking, showers, laundry, and washdown. AMPAC engineers size the correct system for each vessel and design a pre-treatment sequence suited to the operating area. Vessels transiting between coastal and open-ocean environments face changing feed water quality, and systems designed for one condition often struggle in the other. AMPAC modular designs accommodate pre-filter upgrades without replacing the entire RO skid.

For offshore oil and gas platforms, diving support vessels, and government patrol craft, AMPAC supplies ROWPU configurations meeting military and industrial specifications. Units are skid-mounted, containerizable, and designed for operation by non-specialist crew without constant supervision. Remote telemetry options allow shore-based monitoring of system performance and water quality on vessels with satellite connectivity.

Installation support and commissioning assistance are available for new builds and retrofits worldwide. AMPAC maintains a global parts network to support vessels in remote locations with minimal downtime.

Contact AMPAC USA at (909) 548-4900 to discuss watermaker sizing and specification for your vessel or platform.

Seawater Desalination Watermaker (Land Based) - Model: SW9000-LX

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SW9000-LX land based seawater desalination system, 9000 GPD, provides fresh water for vessels & ships. | AMPAC USA

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Seawater Desalination Watermaker (Land Based) - Model: SW10K-LX

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SW10K-LX Land Based Seawater Desalination Watermaker by AMPAC USA provides 10,000 GPD for your water treatment needs. | AMPAC USA

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Mobile Seawater Desalination Reverse Osmosis Watermaker 80,0002 GPD (300m3/day)

Mobile Seawater Desalination Watermaker SW80K-LXC

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6 Reviews

SW80K-LXC mobile seawater desalination watermaker. Fully packaged, containerized, and turnkey system for potable water | AMPAC USA

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Seawater Desalination Reverse osmosis watermaker Mobile fully built is a shipping container.

Mobile Seawater Desalination Plant | SW100K-LXC

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SW100K-LXC Mobile Seawater Desalination Plant is a containerized, turnkey watermaker for potable water production. | AMPAC USA

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Seawater Desalination Model: SW500-LC

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4 Reviews

SW500-LC land-based seawater desalination watermaker: customizable, cost-effective, ready to ship for your water treatment needs | AMPAC USA

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Sea Water Desalination Watermaker (Land Based) SW20K-LX

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SW20K-LX land based seawater desalination watermaker provides 20,000 GPD for marine vessels. | AMPAC USA

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Mobile Seawater Desalination Watermaker System | SW100K-LX

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Get pure water on your ship, boat, or vessel anywhere with the SW100K-LX Mobile Seawater Desalination Watermaker System | AMPAC USA

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Seawater Desalination Watermaker (Land Based) - Model: SW9000-LX

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AMPAC USA SW9000-LX land-based seawater desalination watermaker produces 9000 GPD for various applications. | AMPAC USA

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Sea Water Desalination Watermaker (Land Based) SW80K-LX

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Get pure water with the SW80K-LX 80,000 GPD Land Based Sea Water Desalination Watermaker. | AMPAC USA

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Seawater Desalination Watermaker (Land Based) SW60K-LX

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Land-based SW60K-LX seawater desalination watermaker provides 60,000 GPD pure water for large vessels & facilities. | AMPAC USA

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Seawater Desalination Model: SW6000-LX

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SW6000-LX Seawater Desalination Watermaker for land-based use, producing 6,000 GPD. Perfect for remote sites. | AMPAC USA

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Seawater Desalination Model: SW5000-LX

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SW5000-LX land-based seawater desalination system produces 5000 GPD / 19,000 LPD of pure water. | AMPAC USA

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Sea Water Desalination Watermaker (Land Based) SW40K-LX

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Land based seawater desalination watermaker SW40K-LX provides 40,000 GPD for vessels, ships, and boats | AMPAC USA

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Sea Water Desalination Watermaker (Land Based) - Model: SW4000-LX

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SW4000-LX land-based seawater desalination watermaker. Produces 4000 GPD / 15,140 LPD of pure water. | AMPAC USA

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Seawater Desalination Model: SW3000-LX

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SW3000-LX land-based seawater desalination system provides 3000 GPD for large boats, ships, and various offshore vessels | AMPAC USA

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Seawater Desalination Watermaker SW24000-LX (Dual 12,000 GPD Units on one Skid)

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Dual 12,000 GPD seawater desalination watermakers on one skid for 24,000 GPD total. Model SW24000-LX. | AMPAC USA

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Seawater Desalination Watermaker (Land Based) - Model: SW12000-LX

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SW12000-LX Land Based Seawater Desalination Watermaker: 12,000 GPD / 45,000 LPD for large vessels & marine operations | AMPAC USA

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Sea Water Desalination Model: SW2000-LX

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SW2000-LX Sea Water Desalination Watermaker for huge boats, ships, PSV, MPSV, and AHTS type vessels. | AMPAC USA

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Fully Equipped, Seawater Desalination Watermaker 1500 gallons per day.

Seawater Desalination Model: SW1500-LX

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SW1500-LX land-based seawater desalination system makes ocean water drinkable for various uses. | AMPAC USA

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Seawater Desalination Watermaker 800GPD | 3000LPD

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Get pure water with the SW800 Seawater Desalination Watermaker, producing 800 GPD via reverse osmosis | AMPAC USA

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Seawater Desalination Reverse Osmosis Watermaker 6,000 GPD

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Desalinate seawater for communities & industries with AMPAC USA's 6,000 GPD Reverse Osmosis Watermaker. | AMPAC USA

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Seawater Desalination Watermaker Model SW600 (600 Gallons per Day)

Seawater Desalination Watermaker 600GPD | 2270LPD

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600 GPD Seawater Desalination Watermaker for boats & small ships. Get fresh water from the ocean with reverse osmosis. | AMPAC USA

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Seawater Desalination Reverse Osmosis Watermaker 5,000 GPD | 19,000 LPD

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Desalinate seawater with AMPAC USA's 5,000 GPD reverse osmosis watermaker for large-scale water needs. | AMPAC USA

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Seawater Desalination Reverse Osmosis Watermaker 4,500 GPD | 17,000 LPD

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Get pure water anywhere with the AMPAC USA 4,500 GPD Seawater Desalination Reverse Osmosis Watermaker SW4500 | AMPAC USA

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Seawater Desalination Reverse Osmosis Watermaker 3,000 GPD | 11,350 LPD

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Seawater Desalination Reverse Osmosis Watermaker 3000 GPD, SW3000 makes boat rides safe by providing you pure water anywhere.

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Seawater Desalination RO Watermaker 300 GPD | 1135 LPD

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Get 300 GPD pure drinking water from seawater with this Reverse Osmosis Watermaker. Perfect for marine and remote use | AMPAC USA

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Seawater Desalination Reverse Osmosis Watermaker 2,000 GPD | 7,500 LPD

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Desalinate seawater with the AMPAC USA SW2000 reverse osmosis watermaker, producing 2,000 GPD of pure water. | AMPAC USA

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Ampac USA Seawater Desalination Watermaker 200 Gallons per day.

Seawater Desalination RO Watermaker 200 GPD | 750 LPD

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Seawater Desalination RO Watermaker 200 GPD | 750 LPD by AMPAC USA provides pure water for various applications. | AMPAC USA

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Seawater Desalination Fresh Watermaker Model SW1500

Seawater Desalination Reverse Osmosis Watermaker 1,500 GPD | 5,670 LPD

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Get 1,500 GPD pure water from seawater with this reverse osmosis watermaker, ideal for boaters. | AMPAC USA

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Seawater Desalination Watermaker 1000GPD | 3780LPD

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Produce 1000 GPD of fresh drinking water from seawater with this marine-grade reverse osmosis watermaker. | AMPAC USA

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Seawater Desalination Watermaker for Marine and Offshore Applications, 100 Gallons per Day.

Seawater Desalination RO Watermaker 100 GPD | 380 LPD

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Seawater Desalination RO Watermaker 100 GPD for marine use. Get reliable freshwater from the ocean. | AMPAC USA

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ROWPU SW5000 (5000GPD/19000LPD)

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Military Sea Water Desalination 5000GPD, ROWPU SW5000-ML is awesome for navy ships. To buy this Military Water Purification System available at best price & deliver swiftly, call at 909-548-4900.

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