What is the water Tank capacity 26 Cutwater 40 gal?

[BB marine]

I am in the process of changing my water flush for the head from Raw water to fresh water. I removed the interior forward bulkhead to gain access to the water pump and fresh water hoses. While doing this I looked at the tank. It seemed small for a 40 gallon tank. I measured it 30X15x16 and did some math and came up with 31 gallons outside dimensions so it is actually less then 31 gallons. I checked all-around the tank for a capacity and certification plate/sticker but I couldn't find one. Was the wrong tank installed or is Cutwater's Capacity Spec wrong? A 10 gallon difference is quite a bit. I'm hoping the factory installed the wrong tank, it would be easy right now to install the right one. Any information on this subject would be appreciated.
Brian Brown
26 Cutwater
PORT-A -GEE

 

[Andrew Custis]

Hello,

We use to list the hot water heater separately but we now use a combined number and why you see 40 gallons listed.

Thank you,

 

[BB marine]

I'm not sure I understand that explanation. 30 Gallon fresh water holding tank is installed and a 6 gallon hot water tank is installed and that equals 40 gallons? I actually have 30 gallons of usable fresh water and 6 gals sitting in the hot water heater when the 30 gallons is used. I'm not sure I understand that logic. Misleading capacity. There is room for the 40gallon tank 39"x18"x14". It looks like I have another project added to my list, install a water tank that I thought was in the boat
Brian Brown
26 Cutwater
PORT-A-GEE

 

[Andrew Custis]

Brian,

There is nothing misleading about it. We used to separate the total water capacity but now include what the water system can hold.

 

[knotflying]

Kind of like airplane fuel they will list it as x gallons with x usable. I installed the Airhead when the boat was new and converted the holding tank to water. No holding tank or head issues and plenty of water. 😀

 

[BB marine]

Kind of like airplane fuel they will list it as x gallons with x usable. I installed the Airhead when the boat was new and converted the holding tank to water. No holding tank or head issues and plenty of water. 😀

I use that theory too. I always use the 10% rule. If a fuel capacity is 80 gallons 10% or 8 gallons is not usable. Holding capacity is 80 gal usable capacity is 72. I get that. So my thinking on the water tank is 40 gallon capacity,10% rule 4 gallons not usable and 36 usable. Capacity is the amount it will hold or carry. In this case Cutwater publicizes 40 gallon capacity, In the brochure, online, at the dealership. My mistake is not knowing that Fluid motions includes the hot water heater as a holding tank. 6 gallons of the advertised capacity is in the hot water tank.
1) Water Capacity -36 gallons including Hot water tank. (installed)
2) Water Capacity -40 gallons (Advertised)
As a consumer I'm going with the factory specs. The manufacturer knows what size tank they install.They do 30 gallons! Mike your Plane's manufacturer states Fuel holding capacity and usable fuel and I would imagine you have your own percentage of usable. We Do extended cruising like you. Fuel, Water, holding tank capacities are important. When 40 gallon capacity turns into 27 gallons (10% of 30 gallons) of usable water. It is disappointing. Somewhere along the line there is 4 gallons missing in the advertised capacity. 36 gallons doesn't equal 40 gallons.


You mentioned the Airhead. We have talked to an Airhead representative at two boat shows. The theory sounds great. Theory and reality are two different things. The installation in the 26 Cutwater would be very easy. I'm in the process of installing fresh water flush and schedule 40 1 1/2" PVC pipe for my waste line to the holding tank. While I'm doing this I keep thinking I should install the Airhead. I can use the PVC pipe for my vent line and exhaust it at the transom. The biggest issue is it's size. I would like to see one installed in a Cutwater. What are the issues if any that you encountered with the Airhead?
With the removal of the waste tank I would be able to put an fuel transfer tank in that area to increase my fuel capacity. I will be replacing the 30 water tank with a 40 gallon tank it will fit in the same place as the 30 gallon.
Brian Brown
26 Cutwater
PORT-A-GEE

 

[snydzy]

I asked this question back in August,(viewtopic.php?f=2&t=9640#p66728). I’ve also seen brochures showing both 30 gallon and 40 gallon water capacities on my 2013 R25se. I agree with Brian,...water capacity implies the holding tank carries that much water,... after all, the 6 gallons in the water heater isn’t really usable after the main tank is empty. so what’s the point in stating that it’s larger? I purchased an inexpensive hose meter to find out (after pumping my system dry) and was consistently adding about 28 to 29 gallons on refilling. I also utilize a fresh water head. I can get 4 to 5 days on that (we bring all our potable water) and I never haft to worry about overfilling the black water tank as it is also stated at 30 gallons..

 

[ixlr8]

I can get 4 to 5 days on that (we bring all our potable water) and I never haft to worry about overfilling the black water tank as it is also stated at 30 gallons..

I bet you hope that RT doesn't use the same fuzzy math on the black water tank that they use for the fresh water tank.

 

[S@LTD]

So why doesn't the factory not install a 40 gal tank if it fits in the same place? Given the price of these boats I cannot believe it is a cost issue.

 

[knotflying]

I realize that a discrepancy in size may be important, but in reality no matter how many gallons you can hold or use in the end it is about your historical statistics that matter. I know that I can get a good week out of each of my water tanks. We use about 5 gallons per day. I can stretch that even further if I know we need to. On the other hand, I was on a boat with inexperience boaters and it held 200 gallons. We were out of water in two days. After I explained how to function the water lasted the rest of the trip after the refill. So my point is, knowing duration is more important than quantity. Sure when purchasing you may want to know, but after that it is all about usage.

 

[BB marine]

Good point and I agree. You learn water conservation on a boat. Here's where it really became an issue for me. We have used the boat and learned how to conserve water to the point of how much water to put in the galley sink, how long to run the water for showers when on the hook. We use the water for drinking, coffee, ( we filter water going in the tank and out of the tank and if the water is in the tank for more then 7 days we drain and refill) with this we have been able to get four days out of a tank and still maintain 1/4 tank of water. 1/4 of a tank (40 gallon' 10% rule 36gallons) = 9 gallons ok that gives me enough for the fresh water flush for the head that I just installed.I estimated 5 flushes to a gallon giving me 45 flushes in 4 days I probably will not need that but I also don't want to run out of water. Now 6.5 gallons with a 30 gallon tank gives me 32 flushes. Probably going to run out of water! It sounds petty but when your trying to make accommodations to stay on a 26' boat for a lengthy period of time every little bit counts.
Brian Brown
26 Cutwater
PORT-A-GEE

 

[knotflying]

We carry a case of 16 oz water bottles and 4 gallons of regular water. I always rotate the gallons and fill them at the marina. We use the gallons for coffee mostly and for drinking. Use the tank water for washing up, showers, oral hygiene and occasionally drinking and cooking.

 

[MartyC]

I replaced my 30 gal tank with a 55 gal tank (see album) at the same time I was converting my head to a fresh water flush and changing my 1 1/2" waste hose to a 1" (which ran behind the water tank). Also, I like the ability to carry extra water when I need it. The 55 tank sits in the same area as the 30 gal tank did (between air conditioner and water pump), just a larger footprint. We only use the 'cuddy' for storage so the floor space I lost doesn't matter.