2006 Sundancer 320 Holding Tank Capacity

Jun 14, 2022
32
Marblehead, OH
Boat Info
2006, 320 Sundancer
Engines
Twin 350 Magnum MPI MerCruiser
Just bought my "new to me" 320 and can't find the holding tank capacity anywhere in the manual. I have read online everything from 20 to 40 gallons. Either way, my concern is that 40 gallons of fresh water empties a lot quicker than the holding tank fills. If I understand the system correctly this is because the gray water (shower and A/C drain) all pump overboard? Is that the correct understanding? And before anyone asks, yes, the macerator seacock is closed.
 
You're correct about the gray waters draining overboard. As for tank capacity; if you can get to the tank to measure it, just multiply L X H X W in inches and divide that answer by 231 to give you gallons.
 
It will definitely be in your manual. As well as right on Sea Ray's website in the spec page for your model. And I think there's an info plate on your holding tank.

BUT... going from memory, it's probably 28g.

Yes, you're correct about how the shower pumps overboard... unless the boat has the grey water option where EVERYTHING is plumbed to the holding tank to avoid overboard discharge of any water. You'll have to do some investigative work to figure that out.
 
How do I know if I have the "grey water option"
That's the investigative part. You have to see how/where things are plumbed. Like I mentioned above, nothing will be plumbed overboard, including any sink.
 
It’s pretty easy to research whether all sinks & cockpit drains empty overboard or not.
 
Just bought my "new to me" 320 and can't find the holding tank capacity anywhere in the manual. I have read online everything from 20 to 40 gallons. Either way, my concern is that 40 gallons of fresh water empties a lot quicker than the holding tank fills. If I understand the system correctly this is because the gray water (shower and A/C drain) all pump overboard? Is that the correct understanding? And before anyone asks, yes, the macerator seacock is closed.
Fresh water is 40 gal and holding tank is 28 gallons, only thing that goes to the holding tank is what is flushed down the toilet, I have the same boat
 
Here is the brochure with the specs
 

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Fresh water is 40 gal and holding tank is 28 gallons, only thing that goes to the holding tank is what is flushed down the toilet, I have the same boat
Unless the boat was ordered with the grey water option. Not all boats are built the same. However, the GW option is/was selected only a very small percentage of the time.
 
Fresh water is 40 gal and holding tank is 28 gallons, only thing that goes to the holding tank is what is flushed down the toilet, I have the same boat
Are you able to see the shower water being expelled out the side of the boat or is it released under the water?
 
If the boat does not have the gray water option can I see the shower water being pumped out, or is the exit point under the water?
Yes, it would pump out the side of the boat - above the waterline. Your cockpit sink should just pour out the side of the boat, too. Meaning... it's not that hard to figure this out - don't put too much thought into it :)

FYI, out of curiosity, I looked in your manual - like Prego spaghetti sauce... It's in there!
 
Yes, it would pump out the side of the boat - above the waterline. Your cockpit sink should just pour out the side of the boat, too. Meaning... it's not that hard to figure this out - don't put too much thought into it :)

FYI, out of curiosity, I looked in your manual - like Prego spaghetti sauce... It's in there!
Thank you! Haven't heard the Prego saying in a while, you're dating yourself. Do you know what page of the manual has this spec? On another note, do you have a digital copy (PDF) of the owners you can post?
 
Thank you! Haven't heard the Prego saying in a while, you're dating yourself. Do you know what page of the manual has this spec? On another note, do you have a digital copy (PDF) of the owners you can post?
Yeah, I guess I am! :)

For your second question... look at my first reply ;) (No, I don't recall the exact page number)

EDIT: To be clear, my first post was referring to the spec sheet for your model. But the manual is available on SR's site, too ("owners" section)
 
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Both cabin sinks and your shower/ac sump box will exit through this manifold provided you dont have the grey water option. Your cockpit sink drains out a seperate one in the corner of the port stern
 
Yeah, I guess I am! :)

For your second question... look at my first reply ;) (No, I don't recall the exact page number)

EDIT: To be clear, my first post was referring to the spec sheet for your model. But the manual is available on SR's site, too ("owners" section)
Now I would really like to know where you are seeing the holding tank volume indicated in the owner's manual. Not a big deal since it is in the 3-page specifications document. But, it is not in the Owner's manual. The exact manual in PDF form is not available from Sea Ray documents, so I reached out their support and they sent me the generic Sport Cruiser Manual and said that is all they have avaliable. I searched it for holding tank and it did not show the holding tank volume anywhere as well.
 
Now I would really like to know where you are seeing the holding tank volume indicated in the owner's manual. Not a big deal since it is in the 3-page specifications document. But, it is not in the Owner's manual. The exact manual in PDF form is not available from Sea Ray documents, so I reached out their support and they sent me the generic Sport Cruiser Manual and said that is all they have avaliable. I searched it for holding tank and it did not show the holding tank volume anywhere as well.
OK, let me go back and look... maybe I had the spec sheet in my head when responding and just "thought" it was in the manual as well... be back in a minute :)
 
Look in the table of contents - go to the "basic boat dimensions" section. Prego.
 

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