Lori and I have always maintained that a watermaker is completely unnecessary when cruising the BC coast – so what changed? Well…we spent some time on a boat with one. We still don’t think we “need” one, but the freedom of just using clean, fresh water whenever you want is very alluring. Every swim can end in a fresh water rinse, dishes get a thorough rinse, and water shortages aren’t an issue like they were on our cruise to Haida Gwaii in 2015. They come with a number of costs though: space, maintenance, energy, money – lots of money, and the effort of a significant install. I tend to gloss over this cost over when I take projects on; this time was no different.
We started by doing tons of research. I started by assuming that my search would lead inevitably to a Spectra simply because of their incredible efficiency. But there are more things to think about than litres per amp hour. After a lengthy detour to an AC system that we could design ourselves, we eventually decided on an 50 litre/hour ECHOTec DC system for a few reasons:
- It will run off our existing DC system. We didn’t want to rely on extra gear like a generator (ugh) or an inverter. We normally have an excess of electricity, but will eventually upgrade our solar and alternator to ensure that we’re never short, regardless of the weather.
- They are very simple – the system is essentially a DC motor, a plunger style high pressure pump as used on a pressure washer, and a membrane. Nothing is automated.
- They are a little less expensive than a Spectra – but not enough to be a major factor in the decision.
- It should produce 100% more water in one hour of run time than we currently use per day when we’re being fairly liberal with our water use. We figure a couple of hours of run time every second day will more than meet our needs, even if we turn into water pigs.
- The vendor (Hydrovane) is local and well established.
We haven’t used our watermaker yet, so we don’t know for sure if we made the right call, but the logic and numbers still make sense to us. We’re pretty confident that we have the right system.
We started by having Will and Sarah from Hydrovane visit the boat. Not only are they the vendors, but they are also experienced bluewater sailors with experience living with the ECHOTec model we were considering. We had a great morning talking about their adventures and our plans, along with a thorough look at our boat and the spaces we could use for the various parts of the system. There are a number of large parts that needed a home:
- The motor and high pressure pump. The
pump doesn’t reliably create the lift required to suck water – even with a boost pump to feed it water, it is best to locate it as low as possible. The pair is also big and heavy.
- Pre-filters. These consist of a pair of domestic 10″ housings, plumbed in series. This assembly is fairly large and needs to be easily accessible
- The pressure vessel for the membrane. It can go anywhere, but it’s long.
Will and Sarah brought a pressure vessel along as they believe that this is normally the most problematic component to fit due to it’s length. We tried under our V-berth – it’s tight but it fit. We measured out potential locations for the other major components and placed our order. A month later it arrived in two large wooden crates.
We unpacked the crates and laid out all the parts on our living room floor to check them against the parts list. Everything was as advertised, but the mountain of individual pieces was more than a little overwhelming. Despite the simplicity of basic water making process, the addition of alternate circuits for testing, flushing, and pickling (preserving the membrane from biological growth for long periods of downtime), requires a significant selection of fittings and hose to figure out. Thankfully, the relatively well written instructions helped to clear up some of the questions before we set to work on the boat.
I tackled the major components first: the high pressure pump and motor, pre-filters, pressure vessel, and control panel. We originally planned to put the pump/motor assembly on the cabin sole in the V-berth, but this area was also a prime spot for the pre-filters due to its accessibility. The filters won that tug of war. We settled on sacrificing a difficult to access drawer and previously unused space under the v-berth for the pump/motor assembly.
This installation required that I replace the drawer with a strong shelf to support the substantial weight of the pump and motor and cut an opening for access to the space from above. I glassed the shelf to the hull and painted the compartment before bolting the pump motor assembly in place. I finished this step by using the old drawer front to cover the hole that the drawer used to occupy. I cut a hole in the old drawer front to make room for the motor and provide ventilation, and hinged it to the cabinetry so that I could access the compartment from the side as well as from above.
I finished the pump installation by running a #2 wire from a breaker near the positive bus at the battery box all the way forward to a terminal block. This run will power both the high pressure pump and the feed pump.
The pre-filters and pressure vessel were both easy to fit, requiring only a few holes for plumbing.
The control panel was another matter. We originally decided to install it in a new cabinet on a small counter at the head of the v-berth. I even went so far as to drill holes through the counter and fabricate a teak cabinet. However, the number of wires and hoses connected to the back of the panel ultimately made this location unworkable. We finally settled on sacrificing a small but useful storage space near to the cabin sole and adjacent to the pump / motor compartment.
I thought that the rest of the installation would be pretty simple – it’s mostly plumbing. But there were also two more filter housings to install – one to filter chlorine out of a fresh water rinse circuit and one to house a water hardener – along with the boost pump and a water strainer. Like the pre-filters, the rinse water filter housing and water hardener housings are both domestic 10″ housings and require accessibility and a bit of space. The other issue we were starting to think about was how many spare filters we’d need to buy and store to fit in all of these housings; along with the domestic water filters under the sink, we were now 5 housing all requiring regular maintenance. We thought about this for a while, and finally decided to re-plumb the pressure side of the entire cold water system in order cut that number by one. This was a lot of work, but was worth it as it improved our existing system and cut the number of requires spares by 20%.
The rest of the water-maker plumbing was straight forward, but tedious. Cutting the high pressure hose with a zip disk was easy, as was installing the fittings. Much of the low pressure plumbing is routed from the control panel via 3/8″ hard plastic tubing and compression fittings – I used brass compression fittings and hose barbs to connect them to the boat’s systems. The product water is sent to the tanks by tying the water-maker output line into the vent line – we’ll see how this works – and the raw water is teed into the wash down pump through-hull fitting, thereby reducing the number of needed through-hulls by one. The water strainer and boost-pump are in the same compartment as the associated sea cock, and required a bit of wrestling to hook up.
The test water line – you’d hate to inject bad water into your tanks – is teed into the foot pump spigot in the forward head with check valves in both lines to ensure the the foot pump and the watermaker can only send water out of the spigot, and not back into the system.
There’s more of course, but this covers the majority of the work required for the water maker to function. For now, the feed water through-hull is still closed and, except for the membrane, the unit is dry. I’m a little apprehensive about firing it up – there are tons of fittings and I’m sure some of them will leak. I’m hoping for the best, and will post a report after we have some time living with the system.