Overboard holding tank discharge

[David B]

Originally Posted by a64pilot

An issue with high mounted waste tanks is that the head will have to pump the effluent up hill, meaning the hose will always be full and the Joker valve is even more important as its the only back flow valve, isn't it? If your tank was lower than the head, then if you were careful with hose routing, it could drain after each flush and now no back flow, and I assume your hose will last longer before it permeates?
Not sure though if any tanks are actually lower than the heads though?

Agreed, but the discharge is to the top of the tank, and therefore if the joker valve (anyone explain why that name? - I would prefer to call it a non-return valve) does leak, you only have what is in the hose to run back into the bowl. The reality is that the force of the electric pump - once the bowl is empty and it starts to push air, empties half the hose anyway. Also, if you flush properly there is only clean water in that hose.
We also use de-scaler regularly.
As to lower holding tanks, I noted the tank on a friends Bavaria was under the main cabin sole.
Pluses and minuses for many systems, but I definitely prefer the simplicity of gravity discharge, plus for pump-out, the tank is right under the deck fitting.

[markpierce]

My holding tank is forward-port and above waterline. The bottom valve access requires opening the hanging closet, knocking out an access hatch, and moving personal items at the bottom of the closet. Have a company pump out the tank periodically from the deck access.

[David B]

Originally Posted by markpierce

My holding tank is forward-port and above waterline. The bottom valve access requires opening the hanging closet, knocking out an access hatch, and moving personal items at the bottom of the closet. Have a company pump out the tank periodically from the deck access.

Nice and clean down there - great to see.
Both ours are at the bottom of the basin cabinets in the heads, so you just open the cupboard under the wash basin, and it is in front of you. The aft one is quite deep though, so a bit of a reach.
What is the boat?

[markpierce]

Originally Posted by David B

...
What is the boat?

Seahorse Marine (built in China, owned by American Bill Kimley, better known as builder of diesel ducks) model Coot, 36-foot steel motor boat.

[David B]

Originally Posted by markpierce

Seahorse Marine (built in China, owned by American Bill Kimley, better known as builder of diesel ducks) model Coot, 36-foot steel motor boat.

Good photo - thanks

[botanybay]

Unfortunately in the Chesapeake being applied only to commercial vessels would not be the case, at least when I was sailing there in the 90s .

The coast Guard hated "potty patrol" but it was part of what they were required to do.

Private vessels of all sizes. If it had a head it had to comply.

Since then all of my systems have gone to a holding tank first, with two separate discharge pumps, two separate dip tubes, and a deck pump out.

Two because I sail offshore and don't want to work on a sewage pump at sea.

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