More tank, or water maker?

[MysticGringo]

I have found two boats I really like, and am close to making an offer. The boat will be used as a cruiser/live-aboard in the Caribbean, and the main difference is one has 60 gallons of water, and the other has only 30 gallons of water, but has an autopilot. I will be needing an autopilot regardless, so there is expense in adding it to boat A.

I would like to put a solar power system on either boat, as the Caribbean sun can provide me with abundant power. The question comes, would I be wise to add tankage to boat B which only has 30 gallon tank right now, or instead add a watermaker sized appropriately for my daily usage to keep a 30 gallon tank filled?

As I see it, more water tankage is always a good thing. But that space could be used for storage instead... which would be very useful, especially as the boats I am looking at are not large. Relying on a water maker will be an issue of maintenance, and costs. It is easy to get water in the Caribbean otherwise though, so might not be as big an issue.

What would be your thoughts? More tank, less storage, less cost? Or, less tank, more storage, watermaker?

[ssullivan]

Personally, I would go for tankage. You may find you need it even with a watermaker. I like the feeling of having enough water available to last a month, even though I may never need it. If your watermaker breaks down, it would be nice to have that 60 gallons to drink in an emergency vs. the 30 gallons. If you're not as "survivalist minded", you may find the 30 works, but I'd sure feel better knowing that in a pinch, I had 60.

[Sunspot Baby]

This can be a tricky question. First, I think 60 gal of fresh water is slim storage at best and 30 is completely inadequate. Of course, when we spec’ed our boat we said we wanted ice cubes in our drinks and fresh water showers at will. Your needs may differ.

Adding tankage is tricky because of weight. Assuming there is a place low enough and in a spot that won’t overly affect balance, it is doable. Remember water weighs about 8 lbs/gal.

We use a Pur 40E reverse osmosis (RO) water maker. It gives us only 1 ½ gph, but keeps us in drinking and cooking water. We carry 175 gal fresh water, and it lasts the two of us about a month, maybe a little longer. We do not shower daily and use good water conservation techniques, but otherwise, we use fresh water when we want. The commodore uses fresh water to do dishes, not sea water, but she is very careful with the amount.

Our small water maker draws only 4 amps, so when I run the generator, I run the water maker (assuming suitably clean sea water at location). If motoring, or motor sailing, we do the same. RO water goes into jugs for drinking and cooking. Then when we have all of that we need we will run it into the tanks.

In my case, I am trading diesel for water. The generator uses about ¼ gal/hr and consumption is virtually the same charging batteries with or without the RO. I cannot discern any difference in fuel consumption when motoring (slightly less than 1 ½ gph) or motor sailing (less than 1 gph) when I run RO. Therefore, I consider it free water. That will not be the case with larger RO units, but then you have the luxury of using all the water you want.

If you are where you can fill tanks more often, or get plenty of rain, then you can fill tanks when you need.

Staying out of port requires 3 or 4 things, fresh water, provisions, fuel, and maybe SCUBA air.

You have lots to consider:
How many people will be aboard and how well will they conserve?
How long between opportunities to fill tanks?
Is water cheap or free where you cruise?
What lifestyle/curiser are you?

No one answer is right for every cruiser.

George

[Jon D]

After moving aboard and cruising I would say 30 gal is not a lot of water for a liveaboard. I would consider 60 a bare minimum personally.

We used to be able to make 30 gal last a week but that meant limiting showers, We have since bought a larger boat and added a water maker [300 gal/day]. We now average 15 gal per day for two of us not being frugal at all. The big difference is daily showers, or maybe two on a really hot day, not sweating water usage when doing dishes etc. We can also now do a fresh water rinse after we wash the boat in salt water.

[MysticGringo]

All good points. I guess it is a bit too personal of a question to be answered by strangers.

The tankage, if added, would be in the factory location, so as to keep the balance as close to originally designed as possible.

For my usage... I will likely use much more salt water, than fresh, and usually go a week with no fresh water shower when traveling in the caribbean coast (just a rinse at the dive-shop is usually enough). The water will be mostly for the head, 2 showers a week, and personal hydration (if needed, and jugs run out of water). I do know that 30 gals is not much though... and definately not near enough if I plan on long off-shore work.

Storage space on the boat will be an issue, I am sure... and I would rather use tank space for storage instead. But, want to make sure I am not going to regret it.

Thanks for your opinions... much appreciated.

[SkiprJohn]

Aloha Mystic,
I once made a passage from Hawaii to the Straits of Juan de Fuca and in to Bremerton, Washington non-stop. There were four guys and my boat had 100 gallons of water to start. There were no freshwater showers (except in a squall or two), but we made lots of coffee and hot chocolate and Tang. At the end of 25 days without water replenishment we had no water left. I filled the tanks 3 days before setting out. 22 days transit time on the Pacific with no opportunity to refresh the tanks. There was little rain except when we were busting through a squall or two. We caught a few gallons. After that cruise I wished I had 150 gallons or a watermaker. (Watermakers were rare in the mid 80s.)
Kind Regards,
JohnL

[Euro Cruiser]

Sunspot's done a good job of illustrating the typical watermaker-equipped scenario for a larger, more complex boat. Based on the tank sizes, it sounds like your boat will be smaller and simpler. Personally, I would be very wary of choosing a cruising boat that offers only 30 gals of tankage due to the following issues. See which of these following points seem significant/relevant to you:
1. Are you sure there will be only one crewmember aboard your boat, both in the near future and also beyond? If not, 30 gals just got (potentially) smaller.
2. The Caribbean is a big place, much larger than that strip of islands at the E end that most initially think of. Do you want to have the flexibility to visit other appealing parts of the Caribbean? (Roques, Aves, Haiti's Ile a Vache, Cayman Brac, the Bay Is., etc.) All those places don't provide the ready water access that you described. It would be shame to limit one's cruising because of tank size.
3. Many island nations where you will be cruising have inadequate infrastructure and e.g. water quality during periods of extended rain can plummet noticeably. Ironic if its raining cats and docks and your water tank is empty. (See next item).
4. Does the boat with 30 gal tank lend itself to water (rain) collection using the deck? I think a good general rule of thumb for everyone - big boat or small boat - who sets things up to enjoy a watermaker's output should, first, start with a good deck collection system. And the Caribbean does lend itself to rain collection, but forget about tarps and sail covers as rain is often a product of convection, which also brings windy conditions.
5. How much water will you use on average? If you don't have a firm figure in mind, trying to puzzle this out thru others' opinions (like mine) is flying blind. Your daily consumption rate would, I suggest, be a foundation point for answering this Q.

In all of the above, I'm kinda ignoring your thought about adding a watermaker to the boat with the 30 gal tank. Why? First, because watermakers have a poorer reliability record than any other piece of hardware on a boat. (e.g. check the last SSCA Equipment Survey). Even if you have a watermaker, you may (most likely will) find at some point it won't give you water. Second, because (I'm assuming) you will run a fairly simple boat, you are unlikely to have lots of spare amps with which to power the watermaker. (Also, let's remember that watermaker output will depend on line voltage, so a smaller battery bank - already partially depleted - will not work nearly so well as a bigger one even tho' it's losing the same # of amps. And the larger house bank won't do as well as one being charged by a generator or alternator). I think a wind gen is a great idea for the Caribbean...but it unfortunately will not be sufficient to provide for your electrical lifestyle and an endless supply of watermaker water.

IMO it is feasible to use ~2.5 gals/day while in the Caribbean while showering (cockpit, not in the sea), washing dishes in fresh water, and routinely washing the few T-shirts & shorts one wears, and keeping all the interior surfaces and cockpit seats wiped down. This isn't easy and it requires a few bits of hardware (a brass nozzle-type garden sprayer is one essential item to make showering water-efficient) but it's do-able. So in theory, 30 gals is do-able. But I doubt you will ultimately find it desirable.

Jack

[GordMay]

Notwithstanding, they don’t agree with our personal experience, I won’t argue with any of the earlier comments.

Adequate water is a necessity, and more is a luxury.
Only (your own) experience can determine which is which.

Maggie & I cruised the Bahamas with 20 Gallon water tankage, and a Pur-35 (1.5 gph) watermaker, seldom resorting to shore water, and NEVER to rain-water collection. We had refrigeration, and moderate battery (6 – T105’s) and recharge (35A alt’ & 600W gas gen’y) capabilities.
We bathed daily, utilizing fresh water only for rinsing (Maggie has long hair).
We consumed a gallon of coffee (hence fresh water) each morning.
We were, otherwise & by necessity, penurious with fresh-water consumption.

[Sandero]

The answer to this question requires the following:

How many people will live aboard?

What are their water use habits?

Where will you cruise... in waters with easy access to water fill?

In the leeward and winward Islands you can hop from island to island in less than a day and it hardly seems like you would be away from a water fill. If this is the crusing ground 30gal is certainly adaquate but you may be heading off to the dock frequently... and so what?

I have had Shiva for 20 yrs and she carries 60 gal and I have cruised her and lived aboard for some years in there... and even did a NY to Brazil passage... and never either ran out of water or had to severely limit water use. Mostly I was alone, or with one other person, but have done passages with a crew of 4...

More tankage is always better... but there is something to be said for frequent water changes too.

Oh... I had a water maker which I ran off shore and never in port...

Jef
sv Shiva
Contest 36s

[ssullivan]

Originally Posted by GordMay

We consumed a gallon of coffee (hence fresh water) each morning.
\

Gord, did that slow or speed the passage of time when you had a long leg ahead of you?

[senormechanico]

When we left Seattle for Mexico, my wife and I started with a used PowerSurvivor 35. Two years later after several repairs, it finally died, a victim of just being old. We replaced it with a used PowerSurvivor 80, purchased from a cruiser who wanted some mondo sized thing. The 80 was a much better designed unit. 8 amps @ 12 volts got us 80 gallons per day. Never had a lick of trouble with it.

Our current boat has a only 26 gallons of water tankage (it's a 33' multihull) and Spectra 180 watermaker. It's been trouble free with the exception of minor freeze damage, but I can't fault it for that, just my own negligence. With the Spectra, we get 180 gallons a day for a measly 8 amps @12 volts.

It's not annoying to listen to when it runs, (I can't say that about either PowerSurvivor) and about an hour a day gives us over 6 gallons. We have all the water we need for showers and dishes.

Steve B.

[ssullivan]

Wow, Steve - that's a pretty nice setup and not a huge drain on the electrical system.

[senormechanico]

Not to brag, but if the engine is running and the batteries are at 14 V. I get nearly 10 gph. The 6.3 gph is when the batteries are charged but not getting any assistance. (I've got 4 Trojan T 105's in series parallel)

[Meridian]

How about this...get the boat with the 30 gallon tank and the auto-pilot. ADD another 30 gallon (or whatever size) tank to this boat, along with a water maker. You now have 2 small-ish tanks. Dedicate one of the tanks to water-maker product water ONLY, and dedicate the other tank to "emergency supply" only. This way, in case your water maker takes a dump, or contaminates the tank with salt water, you have a clean back-up supply of h2o.
Redundancy is a very good thing.
John

[Euro Cruiser]

I notice that neither Senor Mechanico (clever moniker!) nor Gord are telling us their tankage is adequate. They are saying their watermakers make/made their tankage adequate. There's a big distinction there when considering the spotty reliability of watermakers.