Water is the variable that shapes an offshore passage more than almost anything else. These guides cover the full spectrum: understanding and selecting a watermaker, installing it correctly, keeping it running thousands of miles from a service technician, and managing your water budget on passages where the watermaker is unavailable or you haven't fitted one yet.
Choosing a Watermaker for Offshore Sailing
Reverse osmosis explained, production rate vs. power tradeoffs, the big three brands, membrane lifespan, and installed cost — everything you need before you buy.
- 12V DC: 12–15 L/hr, 4–8A draw
- TFC membranes last 3–5 years
- $1,500–$8,000 installed
Installing a Watermaker: A Practical Guide
The four components, intake placement, pre-filter train sequence, membrane housing orientation, TDS testing, electrical requirements, and commissioning your first run.
- 50µ → 5µ → carbon pre-filter train
- Target <500 ppm product water
- Dedicated 30A DC circuit
Watermaker Maintenance Offshore
Fresh water flush procedure, pickling with sodium metabisulphite, recognising membrane fouling, cleaning chemicals, pre-filter intervals, and the catastrophic mistakes to avoid.
- Flush after every use
- Pickle for storage >3 weeks
- Citric acid for scale — biocide for bio-fouling
Water Conservation on Passage Without a Watermaker
Tank capacity planning, rain catchment from boom tent and sails, the saltwater wash system, jerry can storage, treating suspect water, and a water budget per person per leg.
- 30 L/person/day minimum in tropics
- 10-min squall can yield 50–100 L
- Saltwater dishes cut freshwater demand 40%
About These Guides
These are editorial resources based on accumulated offshore sailing experience. Watermaker specifications, product availability, and pricing change. Always verify current figures with manufacturers and installers. For marina facilities including water fill stations and potable water access, see the marina directory.