Pumping Out Waste at Sea

[nautical62]

There are several ways to go about it, but I'd re-plumb so that you can pump your holding tank overboard. You didn't mention if the tank is above or below the water line. If it's above, my favorite system is to pump the head into the holding tank and let it gravity feed out. If you are where it's legal to discharge overboard, you can just leave the valve open. If not, you just close it until you are where it is legal and appropriate. No pumping required.

If the holding tank is below the waterline, you can run it to the through hull with your pump in that line and a y-valve to separate it from your other line. Or you can once again have everything go to the tank and then either pump it over or have it pumped out.

[peghall]

Not yet, but I will this weekend, I promise

[Wunu]

You make a good point Peg. It would certainly be preferable with the Y going out the through hull. I had been wondering about stowage for the smelly hose. I toyed with the idea of a shackle connection to rinse it but it seems so convoluted instead of a simple Y valve.
N62, I love the simplicity of the system you describe. Our tank is below the waterline though.

[Ike]

Thanks

[Ita]

......

[Dame.n.Jess]

I have just plumbed our holding tank system up using this as my diagram.

Everything goes to our tank (65 litres) then we can pump to a seacock or deck fitting. its very simple and works well. only thing I can see not working is if you had a small tank.

Damien

[Wunu]

Unfortunately Damien,
Our tank (bladder) is microscopic. I haven't measured for an exact figure but based on relative size to our other tanks, no more than 10 gallons.
This system you pictured seems great.

[peghall]

Size of the holding tank has nothing to do with the way it's plumbed. Damien's drawing lets you see how to do what everyone has been trying to tell you to do.

[Dame.n.Jess]

Sorry I didnt mean a small tank alters the way its plumbed, I meant if everything is going to the tank and the tank is small you will need to empty it every day or two rather than being able to pump out less often.

I like the systems that can bypass the tank and go straight to sea but I wanted the most simple system I could (whilst still being legal) with the least valves etc hence I put everything into the tank.

[Wunu]

Thanks for the info Damien. It is great to have knowledgeable advisors at my disposal. No pun intended! If our tank was larger we could probably feel confident that we would be find pumpout facilities as needed. Thanks for the pic! Super helpful.

[sailorboy1]

All this seems like in the long run a waste of time. Sounds that the whole system is not designed well and is in need of a redo.

Are you really sure that the pump doesn't pump the tank overboard?

[David M]

Put the Y-valve between the head and the tank. This way you are never filling the tank unnecessarily. This of course means in places where it is legal to discharge untreated sewage.

Sanitation tanks should always be above the waterline. This is common sense in case you cannot hold it any longer. You should never have to be dependent on a pumpout station being available.

You ALWAYS want your discharge below the waterline for health reasons. You never want to risk splattering someone with raw sewage.

Also, get a lock for your Y-valve. This makes the Coasties happy when they board you.