Cruisers lives revolve around the three major elements of living aboard.  Weather, Amp Hours and Water.  These essentials of the cruising life are always on the minds of who live aboard.  Weather is a constant concern and is of prime importance.  Sailors are always scanning the skies for any sign of change that might indicate an approaching storm.  Amp usage is a daily issue.  Monitoring the state of charge of the starting and house battery banks is an evening ritual all serious cruisers perform.  Every time any electrical device is turned on the meter in the back of the cruiser’s mind runs.  Every time the refrigerator compressor turns on, the meter runs.  As electronic navigation and/or radio equipment burns amps, the meter runs.  Every evening the “Link 10” or similar device is checked to determine if the generator needs to be run to charge the batteries.  At least several times per week, the cruiser checks the fluid level and adds distilled water if needed and that brings us to the subject of Water and the Plumbing system of Millennium Dragon.   

Water is one of the prime concerns of the cruiser.  This section is concerned with fresh water storage and supply systems, not keeping the Ocean out of the boat or pumping salt water out of the bilge.  The bilge pump systems will be discussed in another section.  How seriously one takes the cruising life style may be gauged by how many times he/she has watched “Captain Ron”, the Kurt Russell movie.  One of the funniest scenes is the “shower, run out of water, hide the salami” episode.  The serious cruiser can hear the water pump (and for that matter, the bilge pumps) running a mile from the boat.

When my wife and I cruise we generally need to “fill the tanks” every 7 to 10 days.  When we cruise we generally swim daily and take “salt water baths” at the port, stern boarding ladder (where the on deck shower head is located).  After swimming, soaping up, diving back in to loose the suds then climbing out and rinsing off with about a quart of fresh water.  If it is a little too chilly to swim or shower at the stern, a “Navy Shower” is taken below.  A 4 to 5 second “wet down” is done followed by soaping up.  Then the soap is rinsed off with another 10 seconds of water.  A shower may be accomplished with several quarts of water.  When there are flatlander guests aboard, some cruisers will stand by the shower water pump switch with a stop watch and turn off the water at one minute.  I am not making this up.  On one cruise to the Bahamas I had a real princess aboard.  After 2 days I started looking for a water leak as we had run the port water tank dry.  She just didn’t ever get it.  The leak miraculously cured itself when the princess departed.

There is a paradox when off shore cruising in the islands.  When cruising in civilized waters (many places, near coastal, USA) marinas and yacht clubs are frequently used.  Use of these shore facilities results in the water supply on the boat lasting several weeks as water fills (and electrical hookup) are part of the docking fee.  Water becomes much less of an issue.  When cruising in the islands, most time is spent at anchor and water may cost $1.00 per gallon.  Water use is a very big issue.  A water maker becomes very important and, even though the vessel’s tanks may hold a week’s supply, the machinery must be operated every 3 days to maintain the health of the reverse osmosis membrane.  The paradox is that on a vessel with a water maker cruising in the islands, the tanks are virtually always full as the water maker must be run every day (more “Amps”).    


Main Keel Water Tanks

The Dragon stores water in two built in fixed keel tanks (over 60 gallons each), one polypropylene main cross beam tank (15 gallons) and a Raritan water heater (.  The fixed keels have several functions.  As flat bottomed structural hydrodynamic forms they provide lift as the boat sails to weather.  This is not of prime importance because, as you know, cruisers rarely and gentlemen never sail to weather.  When at anchor over a sandy bottom in a zone of wide tidal range, the Dragon stands level on her “feet”.  This is very handy if you want to touch up the bottom paint or scrub the waterline.  When on the hard she also stands on her feet (see picture above).  There is no fear of a shore stanchion/prop failing causing the boat to fall over.  These keel tanks also form “sealed” compartments.  If the Keel is holed hitting an obstruction, the boat does not take on water.  The water in that tank may get a little salty but the boat will not take on water.  The keels also protect the Saildrives and rudders.  All things considered I will sacrifice a little windward performance (I rarely sail to weather anyway) for the above advantages.

The port keel water tank supplies cold water to the port head/shower and to the Raritan water heater.  Therefore all cold water to the port (guest) head is supplied by from the port keel water tank.  Also, all hot water to the port head, starboard head, starboard stern boarding step shower and galley sink is supplied by the port (guest) keel water tank.

The starboard keel water tank supplies cold water to the starboard head, the starboard aft boarding step shower and the port main crossbeam mechanical compartment 15 gallon polypropylene potable water tank.  The 15 gallon potable water tank supplies water to the filters in the refrigerator then the cold water spout at the forward edge of the galley sink.  This tank also supplies cold water to the galley sink faucet.


Top view potable water tank ahead main crossbeam port side.  Mermaid AC unit seen to left (port).  Fill is center bottom, overflow middle of frame just to the right of center.


View from starboard head into the mechanical compartment ahead of the main crossbeam.  The water heater may be seen over the top of the 16K BTU Mermaid heat pump.

db_Airconditioner Port Side1

View across mechanical space ahead of the main crossbeam from the port head.  The top of the potable water tank and filler fitting may be seen just over the top of and beyond the port 12K BTU Mermain heat pump.


View down into toward the head of the starboard mechanical compartment ahead of the crossbeam showing top of water heater bottom center and Prosine upper right.

Main Cross Beam Water Tanks

Below the shallow stowage compartments ahead of the main crossbeam are two compartments for tanks and mechanical/electrical devices.  A 15 gallon polypropylene is located in the port compartment medially to the port 12.5K BTU Mermaid heat pump.  A 12 gallon Raritan Water Heater is located medially to the starboard 16K BTU Mermaid heat pump and Prosine 3000 Charger/Inverter.  The port potable water tank supplies water to the filters mounted in the refrigerator then to the cold water spout at the forward edge of the galley sink.  It also supplies cold water to the galley sink faucet.  The Raritan water heater supplies hot water to the entire system (both heads, the galley sink and the on deck shower at the starboard stern boarding steps.


Looking aft along the port edge of the hard top bimini where it joins the traveler.  Note the drain fitting inside the end of the “hand rail”.  The flat zinc to the left is screwed through the hardtop into the aluminum frame below to retard corrosion.


View forward of the aft starboard corner of the hardtop bimini where it joins the traveler.  Note the hose that is wire tied to the vertical structural element.


Close up of the drain fitting at the aft port corner of the hard top bimini.  Rain water flows to this drain and may be directed using a hose into the keel water tank deck fittings below.


The bimini top drain water hose laid out over the starboard keel water tank through deck filler fitting.  Potable water from a dock source or rain water may be used to fill the keel tanks.


So how is water added to the tanks and moved around?  The two main keel tanks each have a deck fitting located at the outboard ends of the “back porch”.  These are standard marine through deck “Water” fittings that are hopefully recognized as different than the “Diesel” tank filler fittings three feet away toward the center of the aft deck.  There are two ways to fill these tanks.  The first, most usual, is using a hose at a dock.  You must be sure to us a hose meant for potable water use, not a common garden hose (they leach lead and other nasty stuff into your water).  The second way is to use the drain hoses attached to the aft corners of the hard top bimini.  The hand hold safety edge of the bimini is also designed to be a “gutter” that directs water to the lower aft outer corners of the hard top.  If you keep the bimini clean, use a filter and add an ounce of bleach to each tank, you can use rain water to fill the keels.  It is amazing how much water flows into the tanks in a very short time using this system.  Once the tanks are filled the overflows are located on the inside of the hulls, just under the bridge deck “knuckle”.  When the tanks are full, water flows out of these overflows.  It is not possible to overfill or pressurize the keel water tanks.

Water Tank Port Keel Pump & Filters

Port keel water tank filters and expansion tank.  The filters are common household units found in any hardware store.  Replacement filters are easy to find and inexpensive.


The port keel water pump is located in the aft most lower compartment of the pilot berth cabin at the port companion way stair bulkhead.  Water from the port keel tank is pumped through the filters above and to the cold water sink and shower supply of the port head.  Also to the Raritan water heater.

Water Tank Pump & Filters Starboard Hull

Starboard keel water tank pump, filters and expansion tank.  Water from the starboard keel is pumped through these filters and expansion tank to the cold water supply for the starboard head, on deck starboard stern stair shower and potable water tank ahead of the main crossbeam in the port mechanical compartment.


The starboard keel tank water pump supplies the starboard head.  The pictured “T” and valve are tapped into the cold water supply.  Opening this valve fills the potable water tank from the starboard keel water tank.

Conserving Water in the Pressurized System -- Moving Water

The port keel water tank pump pressurizes the system that provides hot water to all faucets, shower heads and sinks and cold water to the port head.  The starboard pump provides cold water to the starboard head and the aft on deck shower.  Using the valve in the starboard head medicine cabinet, the potable water tank, port side, ahead of the main cross beam.  This tank supplies the cold water filter under the galley sink that supplies cold water to the galley sink and water to another filter in the refrigerator that supplies the cold water tap at the forward end of the galley sink.  Thus, cold water to the galley sink is double filtered and water to the cold water tap (from the refrigerator filter) is triple filtered.  The potable water tank requires a third pump to pressurize this system.  This pump is located under the galley sink.  The 12 Volt refrigerator compressor is located behind this pump below the sink.  Pictures of this portion of the system are seen below.   


Port head showing sink and shower head.  All water to this head is from the port keel water tank.  Cold water is direct, hot water from the Raritan water heater, filled from the port keel water tank.


Starboard head showing sink and shower head.  Cold water from starboard keel water tank, hot water from port water tank through Raritan water heater.


Full size deep plastic (light) home grade sink with standard home faucets and strainers. 

Standard home grade ice water spout.  Water is pumped from the potable tank through the filters in the refrigerator.

Undersink Cold Water Pump and Refir Compressor

The compartment under the sink showing the refrigerator compressor and the potable water tank pump.  This pump pressurizes the galley sink cold water and the line to the filters mounted in the refrigerator.  These filters (third in the line) then feed the ice water spout at the forward edge of the sink.


View of filters in the medial wall of the refrigerator.  Note the refrigerator thermostat upper left in this pic.  also note the drain hole at the bottom between the filter canisters.  This fitting is plugged with a rubber stopper to prevent loss of cold until it is time to wash out the refrigerator.  There is a water trap in this drain.

Water Maker

The above explains a fairly standard pressurized marine water system that outlines how water is pushed to the sinks, the water heater and the potable water tank.  The only portion of the supply side of the system left to describe is the integration of the water maker into the plumbing, keeping the minimally chlorinated water away from the reverse osmotic membrane.  I have described how water may enter the keel water tanks through the deck filler pipes either using a hose from a dock supply, jerry jugs by dingy or rain water.  Sections above describe how the port keel tank feed the Raritan water heater and the starboard keel tank feeds the potable tank in the crossbeam.  The key to simplifying the integration of the water maker into the system is feeding the potable tank directly and having the overflow vent lead back to the overflow vents of the keel tanks.  The fresh water outflow of the water maker is directed to the potable water tank using the non pressurized side of the fill pipe located in the starboard head medicine cabinet.  When this valve is closed and the water maker is turned on, fresh water enters the fill pipe leading to the potable water tank.  When the water maker is off and the valve is opened, pressurized water from the starboard keel tank flows into the filler pipe and fills the crossbeam potable water tank.  As the water maker reverse osmosis membrane canister is a closed system, water cannot back flow into the water maker when the starboard keel tank is used to fill the potable water tank.

Water Tank Overflow Diversion Valve 2


The overflow vent from the potable water tank ahead of the main crossbeam leads to the red handled ball valve in the left center of this pic.  The center bilge pump through hull discharge fitting and hose (black) is seen to the right of the valve.

When the potable water tank is full using either system, the overflow enters the tank vent pipe.  This vent pipe is split, having a high arm that runs down into the vent pipe for the port keel tank and a lower arm that runs down hill to the starboard vent pipe.  There is a valve in the starboard system located in the compartment with the starboard keel water tank pump.  This valve is left open.  When the potable water tank in the crossbeam is filled using either the starboard keel tank and pump or the water maker at some point it is full and water runs into the vent/overflow system.  As the starboard arm is lower, water flows into the starboard keel tank.  When this tank is full, water flows out of the keel tank vent overboard at the stern.  When this happens, the valve in the starboard compartment is closed.  Water entering the potable water tank is then pushed further up hill in the higher arm of the vent/overflow of the potable water tank and flows down into the port keel tank.  When this tank is full, water runs overboard through the tank vent at the stern.  There is no valve closing off the port side so the potable tank is never sealed.  It simply vents through the port keel vent pipe.     

Water Maker & Timer Switch

Spectra Water Maker pump (center bottom) and reverse osmosis membrane canister (above pump).  The timer switch is seen in the left upper corner.  This unit produces 8 gallons per hour for about 8 amps.  It’s all about water and amps. 

Potable water tank filler valve.  This valve is also pictured above.  To fill the potable water tank from the starboard keel, open the valve.  The pressure water system automatically fills the tank.  Using the water maker, the valve remains closed.


The sea water pump and filters are located below the Bendix washer/dryer in the laundry compartment.  Sea water enters through a through hull/sea cock to a strainer.  Then to a standard pump and through a double strainer.  This pressurized water is piped to the Spectra Water Maker.  Fresh water comes out of the reverse osmosis membrane canister and saltier water is discharged overboard.  The fresh water is piped into the filler pipe lead to the potable water tank in the crossbeam.


The Dragon is equipped with a standard European style small front loading washer/drier.  This product was made for the USA so the wiring is standard 120V 60 Cycle.  The generator is capable of running this unit.  Hot and cold water pipes are connected to the hot and cold sides of the shower feeds.  Effluent is discharge well above the water line through the inside top side of the starboard hull.  When cruising the dryer cycle is seldom used as garments are generally hung out to dry and, once again, the story is Amp and water usage.


The laundry compartment with the Spectra Water Maker to the left and the Bendix washer/dryer forward.  The washer discharge through hull fitting is seen near the forward bulkhead in the lower center of the frame.  The back of the hot/cold water connection box is seen center left next to the Spectra manual.  The pressure gauge for the water maker is see center, top.  The water maker pump is in the small compartment lower left.  The black expansion tank is used to limit the ‘thumping” sound the water maker pump makes as it operates.  Water is usually made between 1100 hours and 1300 hours, using the excess amps produce by the solar panels when the sun is high.  If the batteries need charging in the early evening the water maker may be run at that time also to use the excess amps not utilized by the charging system.  The cruising life is about conservation and proper application of energy.  Alternatively, one may simply purchase more diesel to run the generator.  Life on the water is all about Amps and Water.

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