Holding Tank Question

[kkaasgaard]

Hi All,
I recently bought a 2014 Beneteau 38. I sail mostly in inland waters (san francisco bay) so am happy with the holding tank, which I then pump out in the marina. So far so good. However, I plan to go cruising further afield eventually and with crew onboard the holding tank fills in a few days and black water then overflows down the side of the hull when more waste is pumped into the tank. not a pleasant sight or smell. Clearly I want to be able to empty waste directly into the ocean; bypassing the holding tank when you are cruising (legal when 3+ miles off-shore).

According to the schematics in the manual it should be possible to direct waste past the holding tank and directly into the ocean. But I cannot for the life of me find the valve on the holding tank that is being referred to and shown in the schematic.

Is that really something I would have to install (a y-valve etc) and connect to a below waterline thru-hull? That seems strange to me that a (relatively) new boat doesn't have both options installed from factory - do any of you know anything about this?

Thanks much!
Klaus

[peghall]

HooBoy....getting you sorted out is gonna require LOT more discussion than is practical in a forum. So if you'd like to send me an email (click on my info at the left of this post, you'll see a choice of private message or email...I greatly prefer email), we can set up a time to spend up to an hour on the phone. I do NOT charge anything for that, btw.

Peggie
"If you can't explain it to a six year old, you don't completely understand it yourself." --Albert Einstein

[rbk]

As mentioned you need someone there with you to sort this out. But essentially you need a lockable Y valve for direct discharge. Another good option to add is a manual diaphragm pump that can suck from either the bilge or the holding tank. This allows you to empty the tank when spending time offshore rather than dragging all that crap (literally) with you. You could make it a powered macerate pump but the manual pumps move a ton of water/waste and are an essential backup IMO

[peghall]

He actually needs to be able to flush directly overboard at sea instead of going into the tank at all.

[rbk]

Originally Posted by peghall

He actually needs to be able to flush directly overboard at sea instead of going into the tank at all.

Yes but to be legal in coastal US waters you need to be able to disable direct discharge. A locking valve or the ability to remove the handle, but lockable will get you a thumbs up from the USCG rather than sideways looks and more questions.

[rwidman]

Originally Posted by peghall

He actually needs to be able to flush directly overboard at sea instead of going into the tank at all.

Or, have the sewage go directly into the holding tank (he apparently already has this) and have the ability to empty the holding tank overboard when legal.

To me, this seems the simplest solution, possibly because this is what I have on my boat.

Edit:

"and black water then overflows down the side of the hull when more waste is pumped into the tank."

That's a curious statement. How is it getting out of the holding tank?

[Lodesman]

Originally Posted by rwidman

Or, have the sewage go directly into the holding tank (he apparently already has this) and have the ability to empty the holding tank overboard when legal.

To me, this seems the simplest solution, possibly because this is what I have on my boat.

Edit:

"and black water then overflows down the side of the hull when more waste is pumped into the tank."

That's a curious statement. How is it getting out of the holding tank?

I assume it comes out the vent.
Your solution is better. If OP is going to island hop going to anchor with no ability to pump out, he'll just run into the same problem.

[Cheechako]

A lot of it depends on where and how your sewage tank is mounted. If it is high enough a bottom drain directly to a seacock works great and is simple. Seacock closed and ty wrapped (or wired) and you are in compliance. Open valve offshore and it drains.
Not all setups work with this though. I had a custom plastic tank made tall and narrow to mount to a bulkhead. It was only $100 years ago. This tank drained very well.

[Stu Jackson]

Originally Posted by rwidman

Or, have the sewage go directly into the holding tank (he apparently already has this) and have the ability to empty the holding tank overboard when legal.

To me, this seems the simplest solution, possibly because this is what I have on my boat.

Two choices:

1. ^^^^ that

2. Valve before the tank to go either overboard OR into the tank.

I prefer #2 - why go into the tank if you're gonna pump it out anyway. One less step.

Your boat, your choice.

[jeepbluetj]

I prefer head -> Tank -> Macerator/pumpout. No Y on the head line. But that's ONLY because I can rarely direct discharge in the way I use my boat. For a boat that would be on passage for long times, I'd go with Stu's preferred method.

For the OP - see what you really have. Trace the discharge line from the head to the tank. If there's a Y valve in there, you're done. Just find the right thru hull for direct discharge. If not, and you plan to keep your boat in the bay, I'd add a pump to empty your tank when your in legal discharge zones. (Or maybe you have one... got a breaker labeled "Macerator"?)

Oh, and Peggie wrote the book on this stuff, that's a very generous offer she's making.

[Calif.Ted]

If you can "direct discharge" you can also pump out with macerator, why not do that ? I have a factory option on my boat for direct discharge I've never used, I don't want to run around with that 2" thru hull open and don't want to open or close everytime someone pisses.
Doesn't a 2014 Bene have a gravity drain waste tank that only requires you open a thru hull to empty ? If so just leave it open and it's a direct discharge going thru the tank.

[rwidman]

Originally Posted by Stu Jackson

Two choices:

1. ^^^^ that

2. Valve before the tank to go either overboard OR into the tank.

I prefer #2 - why go into the tank if you're gonna pump it out anyway. One less step.

Your boat, your choice.

I like the fact that anyone can just pee or poop into the toilet without thinking about vales or such. Then, at the proper time, the captain energizes the macerator (and any associated valves) and the poop is disposed of.

In my case, there is only the macerator pump, no valves, so to be legal, I replaced the original push button switch with a key switch and I don't leave the key in the switch.

[mikedefieslife]

I would not recommend the gravity discharge method.

I have that. An outlet going from the bottom of my holding tank to a thruhull. The valve is obviously closed near shore and at anchorages, and opened when off shore to spill the macerated contents of the tank.

The problem is that you end up with a pipe (mine is 2m) full of waste just sitting there for days on end. My piping is brand new so that doesn't smell (yet), but the old thruhull/valve stinks.

[Lodesman]

For gravity to work the tank has to be above the WL - doubtful in a 38 Bene. Probably not an issue.

[Pizzazz]

Halberg-Rassey's have a great gravity discharge system. It is well documented in their manuals, just download and copy the setup to your boat if you want to do gravity discharge.

Otherwise, just download the manual of your boat and start tracing the system.