Mk II water tank capacity

[Mick Laver]

There's been some discussion lately about tank capacities (holding, fuel, water) on our boats. I've always be suspect of that 42 gal claim in the owner's manual for the aft water tank on a Mk II. I know the forward tank is the same 25 gal tank Catalina used on the 30s (in fact I can still see the "C30" in magic marker on the side of mine), but the aft tank just didn't look that much bigger. Today I got a bug up my *** and measured. 28 gallons. I can only guess that someone misread the 2 mark as a 3 on the bucket when he/she measured the aft tank's capacity originally.

That's a big difference, and quite obviously affects planning for long trips if you're not going to see fresh water for a while.

[Jim Hardesty]

Must have been the same bucket they measured the holding tank with.

[Ron Hill]

Mick : I looked at the MKII owners manual (page 4.6.2) that I have and it shows for tankage :

1. Aft water tank - 30 gal
2. Fwd water tank - 25 gal
3. Holding tank - 18 gal
4. Fuel tank - 25 gal

[Jim Hardesty]

My manual and the one here (pg7) claim 42gal.  may have change over the years.

[Mick Laver]

Interesting. The specifications page on the owner's manual archived on the C34 site (Rev: 3/7/03) says 42 gals for the aft freshwater tank. Other capacities the same. Maybe Catalina did change after 1999. If so is it possible to retrofit with a larger tank, and (more to the point) is it worth the effort? I guess I'm the only one who can answer that question.

[Stu Jackson]

Mick, my experience is that the aft tank on our boat is "about" twice the size of the starboard tank (43 gallons vs. 28 gallons).  How?  'Cuz when we use the larger tank it lasts almost twice as long as the smaller tank!

If you REALLY want to save water, use a Scandvik water wand.  Screws right into the galley faucet.

See Reply #4, here for a link to the wand:  http://c34.org/bbs/index.php/topic,6290.0.html

[Mick Laver]

I know this isn't of interest to most C34 owners, but *someday* someone's going to search the archive for Mk II tank specs and it might be helpful. A couple of things:

- The newer Mk II aft water tanks are indeed 42 gallons, at least according to the drawing that Kent at Catalina sent me (see attached.). The length and width are the same as the older Mk IIs like ours, but the height is 13" vs 10" for our '99. The extra 3" comes out to about 11 gallons by my calculations, hence the difference (30 gal vs. 42 gal. claimed capacities.) I'm a bit mystified how the taller tank fits in, since there's a little over 1" clearance between the steering cables and the top of my tank, but I'll let it go. If I need 10 more gallons I'll carry a couple of jerry jugs. And of course use less water ... I ordered one of the slick water wands Stu recommended.

- The aft water tank is substantially higher than the forward tank on a Mk II. I emptied out the forward tank, completely filled the aft tank, opened the valves between the two tanks and let it sit for a couple of days to equilibrate. When I came back the forward tank was filled to the top and the aft tank only had about 4 gallons in it. "So what?" you say. If you fill both tanks and open the under sink valves there's enough head pressure to force water into the forward tank, deforming the top of the tank and compromising the seal on the inspection hole. Water water everywhere. I guess the message is to fill both tanks independently and only open the valve to the one you're using (though if you use the aft tank first it shouldn't matter what you do after that.)

By the way. Kent's diagram shows a 30(!) gallon holding tank.

[tonywright]

Kent's drawing is not quite accurate. On my MKII at least there is a cutout that makes the aft tank lower under the steering quadrant, and higher each side of it. That would solve the mystery I think!


Tony

[Ralph Masters]

Our aft water tank on Ciao Bella is every bit that size.  I think the manual says 43 gallons on the 1987 Mk I.  And as I've said earlier the aft tank sits higher then the starboard tank so water does drain down into that one when both valves are open.
But the holding tank is rated at 23 gallons and I doubt with the placement of the inlet it will hold much more then about 18 gallons.

Ralph
Ciao Bella
MkI Hull 367 1987

[Ron Hill]

Guys : The problem appears to be with the MK II.

The diagram above is the same one that I got in back in March 1998 from Catalina. 
I believe that it truthfully represents the MK I.    A Thought

[Mick Laver]

Yeah, I did notice Kent's drawing omitted the cutout for the steering quadrant. I just figured it was artistic license. :) The length and width are the same, though. If anyone has a later model Mk II (a friend's 2000 also has a "short" tank, so after that) I'd be curious if the tank height is *really* 13".  If it's 10" you have a 30 gallon tank.

Anyone in San Diego willing to look? I'll bring the tape measure and the beer.

[Ralph Masters]

Can't help you out there, I have a Mk I.  I will say this, the math works out on the B182 to be 42 gallons, in fact I did the math and it works out to 46 gallons.  So I would assume, and there's that word, that the others are correct.  I was going to measure my starboard tank this weekend and the holding tank too.

Ralph
Ciao Bella

[Ralph Masters]

Just re-did the math and took off half inch for the thickness of the sides (1/4 in each) and it came out to 42.7 gallons for the B182

Ralph