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Cruising GPD water usage average

7K views 26 replies 14 participants last post by  Stillraining 
#1 ·
Searching the forum pulled up some discussions on watermakers, but none really seemed to note any GPD averages. I will have 5 guys aboard my boat for 10 days, with really no place to replenish the water supply. I've struggled with the notion of adding a $4k+ watermaker for those 10 days. Just doesn't jive with me to spend that kind of money for something I won't use that often.

So, I have three tanks totalling 222 gallons. I figure for water consumption, using nice round numbers that if all of us were 200lbs, we'd need 128ounces per day for 10 days which equals 7.81gpd. Times 5 crew is 40 gallons. I can carry that in water cans.

How do you figure usage for cooking, quick pots/pan/utensil rinse and a shower, say, every other day?
 
#2 ·
Sorry no showers. You have 222 gls of water; 10 days planned for five people. That makes for each 4.4 gl a day for each of them... Nope! No Showers.
Recommend that you could if there is room 5 gls of bottled water per day. That equals out to to 12.5 cases (4 gl per case). Still no showers but you will have enough for cooking and drinking. This is addition to your tankage. and up the water to 5.4 gallons per person per day.
 
#3 ·
I think 4.4 gallons per man per day (which is what you've got) will be lots. Just measure your usage after 2 days and make some adjustments if you have to.
 
#4 ·
Most offshore races recommend 1 gallon per person, per day. That would be 50 gallons, and includes cooking, but nut not washing dishes or showering. Also, unless you're using a solar shower or some other method that can help you keep precise track of water usage, showers are going to eat up more water than budgeted. I'd recommend using a salt water shower with a fresh water rinse instead. Same thing for the dishes. :)

If you've got 200+ gallons of tankage and carry 50 gallons in jerry cans for drinking, you can use the 200 gallons for showers, washing and rinsing.
 
#5 ·
Thanks for the advice. Showering is obviously optional. We'll be on the hook two times about every 3rd day, so I figure we can wash in the ocean and then fresh water rinse from my transom shower hose.

Agreed on doing the dishes in the drink and then rinsing fresh at the sink.

Sounds like you all are suggesting I could make due just fine. I'd prefer to spend money on a new Racor filter system, and possibly some solar panels.
 
#6 ·
Given that others have made far longer passages in boats with less water tankage, you should be fine.
 
#7 ·
Baja this Fall?

Did I read your "broach" thread correctly that you are Baja bound this fall? Is that the ten days/five guys trip? You may want to give that water maker a second glance. Most of our friends who have gone cruising Baja and western <?xml:namespace prefix = st1 ns = "urn:schemas-microsoft-com
Mexico</st1:country-region> installed water makers and the one of the two who did not is bringing one down to P.V. to install it there. The guy who did not, did very little cruising there before bashing home. On the Pacific side of <st1:country-region w:st="on"><ST1:pMexico</ST1:p</st1:country-region> water isn't plentiful, municipal water suspect, and jerry jugging it out to an anchorage is not much fun. It just os happens that I'm in the final stages of installing a Spectra Ventura 150. Pretty complicated and the yard work (you may need 1-2 new thru hulls) and installation will bring the final tab well over the $4,400 purchase price. The downside to the unit is you need to make fresh water at least once every five days to keep the osmosis membrane from clogging up. They have a controller that will do an automatic back flush with fresh water every five days or you can "pickle" the membrane with a special compound that is good for up to five months storage. The other downside is the unit is a bit of a power pig as it chews up 9-10 amps per hour of operation. On the other hand, once, back in the 80's, I caught amoeba dysentery and I wouldn't wish that on anyone.
 
#8 ·
Did I read your "broach" thread correctly that you are Baja bound this fall? Is that the ten days/five guys trip?
Yup, that was my broach thread, and yes, we are Cabo bound this fall. I sent a note to my crew asking their opinion of going without the $4k watermaker. The best response I got from one of my crew was this...

..."I recently discovered that neither the Nina, the Pinta or the Santa Maria had watermakers."

The other funny response was that they preferred I spent money on power generation so they could run their hair dryers before cocktail hour.

I think I have the appropriate crew for the ride south :)
 
#12 ·
In the blazing heat of the Gulf of Mexico, each man was drinking... drinking alone now... 4.5 litres (one UK gal) per day. So each man is going to need about 50 litres for the trip, drinking only. Multiply that by 5, and add a margin, say 300 litres, all up. (66 UK gal, say).

Forget the idea of squeaky-clean showers, either that or get that water maker. The fastest shower ever taken by us was 5 litres. Instead, use a bucket of seawater and some salt water soap.
 
#14 ·
I get by easily with 2.5 to 3 gpd when singlehanding, including washing dishes, and a saltwater wash & freshwater rinse off the stern instead of a shower in the head. Underway, you can wash down with a bucket on the foredeck and then rinse.

When the Admiral's aboard, it's a different story!
 
#15 ·
Spend a lot less money to get a salt water foot pump & faucet installed in your galley sink and use it to wash and rinse the dishes. Turn off the power to the fresh water pump and make everyone pump ALL the water they use and you'll find that your 222 gallons will last three weeks at least. I raced twice across the Atlantic on boats that carried considerably less water than you do but still had nine man crews and never had any problems with water shortages. You are surrounded by water, use it. Just use the stuff you carry for rinsing and drinking.
 
#16 ·
sailingdog said:
If you've got five guys that need to run hairdryers before cocktails, you're in trouble IMHO. I don't believe in wasting valuable amp-hours on a hairdryer unless it is for a cute boat bunny.
Don't tell them, but I also don't have an inverter...or a cute boat bunny for that matter:)

Spend a lot less money to get a salt water foot pump & faucet installed in your galley sink and use it to wash and rinse the dishes.
I already have the salt water foot pump and faucet for the galley sink. I also have a transom shower hose.

Sounds like the voting public would vote no on the watermaker...thank God!
 
#17 · (Edited)
Not the same I know but when we took our Sea Ray out for 10 days in the Gulf Islands every year the Wife my 3 daughters and myself...we would take along a 6 gal drinking/cooking water jug and we never used it all up...

We did have 1 case of bottled drinking water, 1 case of gator aid and 2 cases of beer in addition...

The girls needed or more correctly wanted a quick shower every day so Id give them a few short squirts on the swim step each evening...Our tank age was 40 gal and we would have to fill that up once again for a 10 day trip.

So thats 80 gal giving daily short rinses to 5 people ( every other day for me )... and 6 gal drinking /cooking water...( we use paper plates ) ...How I metered it will be different now in the sail boat but having a 6 gal hot water tank thats warmed by engine heat, when the hot 6 gals is gone shower-es were over for the day...)...and it really does help conserve if someone else is controlling the water flow rather then the person showering..Mexico heat will be different but both times Iv been there I cant say my water consumption has increased that much...BEER maybe...Im not a big water consumer by nature..I drink maybe 24/36 oz per day at home...including coffee

When you do decide to put in a water maker ...Build one yourself...There are plans/parts on the web for half what you can buy one for..and you will end up modifying a bought one to fit your space and or requirements anyway..
 
#18 ·
Just remember that when you have more than one person on board, each of those people will have their own ideas on water conservation and what is their fair share of the water. And you usage may go beyond of what you consider normal usage.

And the one person you want "CLEAN" on your boat is the Cook. So you could consider a rationing of shower water for that person and lots of hand washing water also... Most of the time it could be sea water... but I have seen waters in some areas that are really silted up and you would be piling dirt upon dirt if you showered with it. :eek:
 
#24 ·
A very good point, and one I've struggled with. I am planning to bring the strongest filtration system I can possibly find so as to de-bug the water going back into the tanks. I also have a small Brita unit attached to my faucet. I'm sure given the 200 other boats in the Ha Ha I will find out where to get decently clean water that I can then zap clean. The UV sterilizer is a good idea. Will look into that as well.

Gary1 - What's up with that delivery crew? Sounds like a bunch of hooligans.
 
#20 ·
If you do not want a watermaker and plan to store water you can add a Ultraviolet Sterilizer to your water system, that way you will take care of the organism growing in the stored water in the nice hot weather. You may also wanna boil the water stored in jugs and stuff specially if it is "natural spring water" after a few day in the heat.
 
#22 ·
Welcome Waterguy....apt name for your first post topic...:)

Wouldn't a little chlorine be easier and it wouldn't require curent draw...Good Idea but I was just thinking conservation on all sources including power/fuel..
 
#21 ·
For what it's worth...

Five of us took the boat to the Dry Tortugas (what a fitting name!) for five days of diving.

Island Breeze carries just under 400 gallons in two tanks. After five days with at least one dive a day, and two on several days, we arrived back in Key West operating on the larger tank, which holds 187 gallons. Bear in mind that we picked the wrong time of year for the trip, and had to deal with 'Sea Lice' (baby jellyfish), which meant a good rinse after each dive. Diver and his equipment, too or misery followed.

Meanwhile we cooked, cleaned, etc. No, we didn't waste water, but we didn't scrimp, either.

BTW, we do have a watermaker aboard, capable of making 400 gallons a day or 16.7 gallons an hour, but it has never been turned on since it was installed. The 400 gallons have taken us to the Bahamas, the Dry Tortugas and I can't tell you how many dive trips in the keys, and we've never used more than one tank of water unless there were women aboard. Even then, the second tank was barely touched.

That all being said, the delivery crew (4 guys) who brought the boat from South Africa to Ft. Lauderdale ran completely out of water before they hit Antigua, and that run took them 5 days. The delivery captain left his own notebook and the official ship's log aboard, and that bunch were, IMHO, lucky to survive the trip. They ran out of water a day and a half out of Antigua, ran the genset without oil and seized it, got it running again and the blown out front and rear seals blew oil all over the engine room. They nearly had a mutiny because one of the crew was...odd.

For myself, I like to think that you can get by on about 2.5 gallons of water a day unless it is blistering hot, which the run from LA to Cabo will be. With that in mind, either carry more water, or an awful lot of gatorade. Becoming dehydrated leads to heat stroke, and that is no laughing matter when you're offshore. I had to start an IV on a guy in the Bahamas to rehydrate him, and it was still nip-and-tuck for a few hours.

Rule of thumb: If your urine is anything but faintly yellow, you're dehydrated. If it's dark yellow and stinks, you need to stay out of the sun, and drink as much NON-ALCOHOLIC liquid as you can, and then drink some more.

Have fun, and safe voyage.

Cap'n Gary
S/V Island Breeze
 
#23 ·
Chlorine is OK, But the taste and odor bad. The UV Light draws less than 1amp of power and if hook up right it will only run when the water pump is on. The water from the tank is runs through the UV before getting distributed. About the name I have a water company in Miami, FL and this Forum came out on a google alert that I place everytime a watermakers topic comes up in the web.
 
#26 · (Edited)
I've read in more than a few articles that some cruisers use hydrogen peroxide(3-5 %) in their tanks which would eliminate the chlorine taste. IIRC, 1/4 cup for every 100 gal. did the trick and would run the 'drinking' water thru a filter of choice. I do not recall if Mexico was part of the cruising area in the articles, but I came away from the articles with the impression the hyd. peroxide killed all but the nastiest particulates. Cheap and comes in it's own non-corrosive container!:cool:

As for drinking 'watermaker' water, I did that for 6 days on a trip. I was not familiar with the system, but wished we had one of those "Waterworld" gizmos for recycling...not too tasty!:rolleyes:
 
#27 ·
Well I'll be...

We have the older version of this unit in our house that uses a patented solid carbon block to filter 99.9% of all impurities including pathogens..

Now manufactured with...what do you know ...a UV disinfector also...

About 600.00...a little spendy but guaranteed to meet specs...
 

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