Cruising / Liveaboards with small holding tanks

[simonpickard]

Hello all,

I've noticed a lot of newer production boats have very small holding tanks. Ours is coming with a 32ltr / 8.5 gallon holding tank.

This seems pretty standard in a lot of boats these days.

For this size of holding tank, and for people on smaller boats, how do you manage? Do you have to pump out every 2 days? Any tricks I'm missing?

There must be a lot of people with the same issue, just wondering how people do it?

Regards,
Simon

[JK n Smitty]

Use minimal water to flush. In a lot of populated areas the EPA has funded pump out boats that will come around once a week or so for a small fee or free. We hold 14 gallons and can usually go about a week. Good excuse to leave the dock and go out beyond 3 miles for a sail.

[SV THIRD DAY]

"If it's Yellow be mellow, if it's brown flush it down"



We live aboard with a family of 4 and a 38 gallon tank...we pump out once/week.

[simonpickard]

Do some systems have a switch then for 1's and 2's? 1's go stright outside?

[JK n Smitty]

Originally Posted by simonpickard

Do some systems have a switch then for 1's and 2's? 1's go stright outside?

That is still considered a discharge and is illegal in no discharge locations. If the US Coast Guard catches you doing it you will receive a hefty fine. They require that the Y valve be locked in the holding tank position. If they board you and it's in the hold tank position but not locked you can evan get a fine for that.

Other countries will have their own laws but generally the same. You don't discharge near shore and definitely not in a crowded anchorage.

Sadly many people do ignore this and either discharge constantly or intentionally discharge in areas the shouldn't (use macerators). Just a d$@k move.

[simonpickard]

I've got a lot to learn on this subject, and it seems to change in different areas.
I thought a lot of sailers just went over the side. Is that illegal also?

I do agree though, if you're around others it should be a no-no. Don't do anything to the water you wouldn't want to swim in yourself.

[Horror Hotel]

8 gallons will be a pain in the ass, 20 would be better, 35 and a bottom suction mounted pump would be perfect. That's unless you could have a straight through gravity drain. With 8 gallons here in the US you would be looking for pump out constantly, always be full, risking plugging your tank vent, or spraying sewage out the vent when it's full. I have 35g and can go 10 days on average. Better safe than full. Most of the US is a no discharge zone. Who wants to spend a day looking for a pump out if the diesel and water are full? Go big and have a electric pump so you can dump when it's legal.

[simonpickard]

I totally agree, but the fact is now a lot of newer boats come with very small tanks.
I might look into trying to install a larger one.

Or I guess there's always the composting head road if things start to give me the, er.. sh*ts.

[valhalla360]

Composting toilet is the answer we found:
- Solids only need disposal around every 4-6 weeks (with full time use by 2).
- Liquids we can go 3-4 days before switching to the backup container. (it can be carried up to any shoreside toilet, so no searching for or paying for a pump out. If you are in legal waters, dump it overboard. Sad that the rules aren't more realistic.)
- No smell, nothing to clog, if you let it sit at the end of the season the solids are no more offensive than potting soil.
- Side benefit is it's lighter than a holding tank system.

If you do keep the raw sewage system, I suggest using an appropriate amount of water. Too little and you encourage clogs.

[Mycroft]

We have 18gal and can go a week between pump-outs with two people. A new to us boat and we tried going two weeks, but ended up overflowing the tank. Lots of bilge cleaning and $70 for a replacement vent filter and I'm a lot more careful.

8 gals would be a royal pain and I would start looking for the space to install a larger container.

[Dale Hedtke]

Hypothetically, it makes sense to only put "solids" into the head. "Liquids" can be disposed of over the side, down the sink, etc. Men (and some women) regularly pee over the side. Women can consider placing a small cup in the head's bowl and then disposing down the sink. This makes a big impact on the liquid volume in the holding tank.
I doubt this is legal, but I don't see the actual harm.

[Mike OReilly]

Wow Simon, to my mind 8.5 gallons is tiny. How large is your boat? Where are you expecting to cruise? How many people on board?

Before we went with a composting head (which I would highly recommend), we had a 25 gallon tank on board. With great effort we could go about three weeks with two people on board, but that involved sending most liquids over the side (both his and hers). All flushing was done with minimal water.

As Valhalla says, get a composting head (or make one) .

[rw58ph]

You might be able to install a larger sanitation tank some where, have two small tanks and/or a sanitation system.

When we bought the Eagle, it was set up for crusing, it had a 10 gallons Microphor sanitation system that could be used as a holding tank but way to small. So we installed a 50 gallon holding tank, but had to do some engine room re arranging to make room and get it in place. Being we are a dock condo queen we are pump weekly when at the dock, the 50 gallon holding tank will last us a couple of weeks and when out/bout we use the Microphor sanitasion system We try to use dirt restrooms when ever possible.

[chuckr]

simon -- as mike said above -- all depends are where you are cruising - how many people - how big a boat - how long out - ect

if an afternoon - what is the problem - if a caribbean crossing or down island run no issue with what you got

but a couple of days in the cheaspeake for 6 people might be an issue

so more data please

[SV THIRD DAY]

We also have an electro scan unit aborad and love the thing...
They sure are not cheap...but it also lets us not need to use the holding tank when not in a NDZ.