The water maker installation actually started in the spring of 2004, before we left Houston in June of 2004, but was not completed until December of 2004. The decision to have a water maker was not a difficult one. We had been cruising with some friends in the Bahamas in the fall of 2003 who had a water maker on their boat. It was really great to come back from a day of diving, and take a nice, fresh-water shower. The relief of not having to search for a water source was wonderful.

The difficult decision for the water maker project was to determine what type of power resource to use, i.e., 12VDC, engine-driven, or 110 VAC. Each type has it advantages. Once that decision was made, we had to determine where in the boat to locate the unit. The engine-driven unit was out for me, because there was no room on the front of the main engine for a power take-off. The generator had already been installed, so using a 12VDC was not our only option. The decision was to go with a 110VAC unit.

Water makers are a very expensive investment, running anywhere from $4,500.00 to $7,000.00. This was way beyond my budget. I had talked to the friends with whom we went cruising in the Bahamas in 2003, and with some other friends around the Clear Lake area, about the expense problem. The  consensus of opinions was that one could build a good unit out of off-the-shelf parts, and that would save a bundle. Most of the water makers sold have a bunch of bells and whistles that allow making  water to be very easy and automatic, but those options drive up the price of the unit substantially. With the exceptions of the feed pump and the high pressure pump, I elected to do everything else manually. I would use my tongue to test the water quality. There were some numbers being thrown around that suggested one could build a water maker for $500.00. It sounded good, but this turned out to be unrealistic. I was hoping that I could get the job done for $1,500.00-$1,800.00. Even this figure turned out to be too low, but I was able to keep it under $2,200.00. If you are interested in the actual construction of the water maker, you can look at the drawing that I am using to explain the project. Also, you can look at the parts list that contains a list of the parts used for the project. This list includes part numbers, prices, and links to each vendor and/or manufacturer.

I decided to put the water maker in the 'storeroom' (a converted second head), under the bottom shelf. I already had the 12 VDC refrigeration system, and some of the ice-maker controls in that area. I did not have to move the refrigeration system, but I did have to move the ice-maker controls. I emptied the bottom shelf in the storeroom and temporarily removed it so I could have room to work. I then moved all of the controls for the ice-maker into the area where the ice-maker compressor was installed. I was able to get this done and confirm that the ice-maker was still functioning!!

I decided that the deck plate for the motor and the high-pressure pump should be of plastic as I did not want rot with a wooden deck or corrosion with a metal deck. I was able to find a 1/2" piece of acrylic to which I could bolt down the motor and the high-pressure pump. I used carriage bolts to bolt the parts down. Because I had used a plastic deck, I heated the bolts and then dropped them into the holes. Instantly, I had a square hole for the carriage bolt to lock into. Once I got the deck made, I fabricated supports for the deck that attached to the hull. These supports were made of fiberglass. When the plate was built, and the motor/high-pressure pump deck was firmly bolted into place, it was a matter of getting electricity to the motor, and water to and from the water pump.

The electrical wiring was very straight forward. I wired a breaker from the AC side of the electrical panel and ran 10 gauge wire to the motor. The motor is a 1 1/2 HP 110 VAC Baldor unit. For more detailed information on the motor, please look below the bottom of the parts list.

Getting the water to and from the high-pressure pump was much more involved. The water flow is illustrated in the included drawing. I will explain some of the decisions made. The first decision was to determine from where to get the raw water. I did not want to add another pump to the boat, so I decided to use the raw-water wash-down pump as the feed pump to the water maker. As the raw-water enters the boat, it goes through a strainer and then into a PVC manifold. From the manifold, the raw-water goes through a second strainer before entering the wash-down pump. I had to upgrade the pump that I was using as it did not have the necessary capacity. Based on input from Great Water Inc, I used the Jabsco Sensor Max as the feed pump. I had been thinking about making it possible to switch fresh water to the raw-water wash-down system so we would be able use fresh water to hose off the boat, or shower on deck after a dive trip. I also needed a way to get fresh water into the RO (reverse osmosis) membrane for those occasions on which I would not be able to use the system for 30 days (in which case one must pickle the system) or less (in which case one would leave fresh water in the system). I installed a three-way valve on the input to the feed pump/raw-water wash-down pump. This is where my drawing starts. Following the feed pump, there is a second three-way valve that switches the output of the feed pump to the on-deck wash-down outlet or to the water maker. The water that goes through the water maker goes through three filters. The first filter is a 30 micron filter, the second filter is a five micron filter, and the third filter is a petroleum filter. I know that may sound like overkill, but you know me by now!! After the last filter, there is a third three-way valve whose output goes to the high-pressure pump. This valve can switch the water from the filters or allow a pickling solution to be pumped into the system if the system will not be used for over thirty days.

From the pump, the water enters the RO membrane. From the RO membrane, the water goes to the adjustment valve, which is on the control panel. This valve adjusts the pressure of the water through the RO membrane. The pressure is usually adjusted to between 600 and 700 PSI. There are two outputs out from the RO membrane: raw water (the brine), and product water (the fresh water). The raw water goes through the adjustment valve and through a flow meter, and, from there, to an overboard discharge. The product water goes through a flow meter to a three-way valve on the control panel. This valve switches product water to the galley sink outlet for tasting and quality assurance, or into the fresh water tanks. The output that goes to the fresh water tanks goes through a three-way valve that switches between the port and starboard tanks. The input to the fresh water tanks goes to the fill hoses, and into the tanks. When the tanks are full, the excess product water overflows overboard. All the fresh water tank overflow hoses were replaced during the installation.

So far, the system has worked great. It draws about 10 amps ACV when it is running at 700 PSI. At this setting, I am getting about 15 GPH of product water. Depending on the boat's location, and the amount of sediment in the water, the first sediment filter has to be changed frequently, but I am very pleased with the system. If I had to do it over again, I would put some kind of sound-proofing around the motor and high-pressure pump as they are a bit noisy. I may do that in the future.