Cruising GPD water usage average

[Vitesse473]

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?

[Boasun]

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.

[Plumper]

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.

[sailingdog]

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.

[Vitesse473]

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.

[sailingdog]

Given that others have made far longer passages in boats with less water tankage, you should be fine.

[GeorgeB]

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 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 Mexico 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.

[Vitesse473]

Originally Posted by GeorgeB

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 :-)

[sailingdog]

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.

Originally Posted by Vitesse473

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 :-)

[max-on]

Originally Posted by sailingdog

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.

Now we know the 'true' reason for the inverter!