Watermakers for fishing boats
On a working boat, fresh water is consumed by the job as much as by the crew: washing down, rinsing gear, topping up. Demand is high and lumpy, and the boat usually has machinery running anyway.
The power reality. Most working boats have generator capacity or a large alternator, so the kilowatt-class systems are viable and give the best output per dollar.
What matters on fishing boats
Deck washing dominates
Crew drinking and cooking is a small share of a working boat's fresh water. Size from the whole job, not the galley.
Dirty water is hard on prefilters
Working close inshore, in river mouths or around a busy harbour loads filters far faster than clear ocean. Budget for that.
Vibration and mounting
A workboat is a harder mechanical environment than a yacht. Mounting, hose support and chafe protection deserve more attention than the spec sheet.
Simple beats clever
Manual controls that a deckhand can operate and a skipper can diagnose often outlast an automatic system on a working vessel.
Shortlist for fishing boats
The 8 best matches of 25 that suit fishing boats, ordered by litres per hour. Run time and energy below are for 160 litres a day.
| System | Power | Output L/hr | Draw W | Wh per litre | Price |
|---|---|---|---|---|---|
| Frame AC 240L Torrent, auto Rainman | AC 240V | 180–264 | 2,800 | 12.6 | $15,089 |
| Frame AC 240L Torrent, manual Rainman | AC 240V | 180–264 | 2,800 | 12.6 | $12,089 |
| Zen 150 Schenker · spec unconfirmed | 12/24/48V DC or AC | 150 | — | not published | on request |
| Portable AC 140L Rainman | AC 240V | 100–154 | 1,250 | 9.8 | $5,329 |
| Portable Petrol 140L Rainman | Petrol | 100–154 | — | petrol | $6,731 |
| Portable 48VDC 140L Rainman | 48V DC | 100–154 | 1,250 | 9.8 | $6,240 |
| Modular AC 140L Rainman | AC 240V | 100–154 | 1,250 | 9.8 | $5,460 |
| Frame AC 140L, auto Rainman | AC 240V | 100–154 | 1,250 | 9.8 | $11,168 |
Common questions
- What size watermaker for a fishing boat?
- Include deck washing, not just crew use. Four crew at 40 litres a head is 160 litres a day before wash-down, so 100 to 240 L/hr is a realistic range depending on the job.
- Can a watermaker handle harbour water?
- The intake should be placed to avoid contaminated or silty water, and prefilters will load much faster than in clear ocean. Making water while working in a river mouth or a busy harbour is not recommended.
- Is a watermaker worth it on a workboat?
- It depends how far you run and what carrying water costs you in tankage and time. For boats working several days offshore it usually pays; for day boats returning to a wharf, usually not.
Guides that go deeper
Not quite your boat?
How the shortlist is built. 160 litres a day is 4 aboard at 40 litres each — a planning figure for this kind of boat, not a measurement of yours. The list is filtered to systems whose power source suits fishing boats and ordered by litres per hour. Every figure is the manufacturer’s rated output and draw; Wh per litre is one divided by the other. Methodology.