Marine Seawater Desalination

The product line covers commercial fishing boats, recreational yachts, sailing catamarans, passenger ferries, and small cargo vessels. Units are sized and configured for each application, with compact horizontal or vertical mounting orientations. Corrosion resistance is built in throughout, using 316L stainless steel, fiberglass reinforced plastic, and marine-grade fittings rated for saltwater environments.

The marine watermaker range produces 50 GPD at the low end for a small cruising sailboat up to 2,000 GPD for a large commercial ferry or fishing vessel. Mid-range units at 200 to 500 GPD suit most liveaboard yachts and small commercial craft. System selection is based on daily water consumption plus a 25 to 30 percent safety margin for hotter days and cleaning needs.

Yes. Units up to approximately 300 GPD are available in 12V or 24V DC configurations, drawing 7 to 15 amps depending on capacity. This allows operation directly from the vessel alternator or solar charging system. Larger units above 300 GPD require AC power, typically 120V or 240V single-phase from an onboard generator or shore power connection.

Membrane life in marine service is typically 3 to 7 years depending on operating hours, feed water cleanliness, and whether the system is flushed with fresh water when not in use. Fouled membranes show reduced output and higher operating pressure. FILMTEC and equivalent replacement membranes are standard sizes available from AMPAC USA or marine chandleries worldwide.

Biological fouling is the main risk during prolonged idle periods. The correct procedure is a fresh water flush after the last use, then pickling with a sodium metabisulfite preservative solution if the layup exceeds two weeks. AMPAC USA systems include a fresh water flush valve as standard. Preserved membranes can remain idle for up to 12 months without damage.

Marine-grade spiral-wound membranes reject 99.4 to 99.6 percent of dissolved salts at standard test conditions. From typical open ocean seawater at 35,000 TDS, product water TDS comes out at 140 to 210 mg/L, well below the 500 mg/L WHO potable water guideline. Product water quality improves in cooler water and declines slightly in warm tropical surface water.