B 381 - Holding tank is too small!

Nov 11, 2016
4
Beneteau 381 Midland, Ontario
We bought a 2000 B 381 in August. Lots of projects to work on for the Spring and one is looking at different holding tank options. We are the 4th owners and the previous 3 were all couples who only day sailed..I have a family of 4, we are away from shore 4-5 days at a time and we need more capacity (how else can I say it?).
I measured the current unit at a minuscule 19" X 13" and it is installed on the shelf of our starboard cockpit locker. My questions are 1) should I put a larger tank into the locker that eats up valuable cruise gear space or 2) install a unit inside the head right behind toilet? Lots of space here but would need to fabricate some sort of containment wall or holding tank locker.
Any thoughts / ideas? Thanks.
 
Dec 2, 1997
8,946
- - LIttle Rock
The tank doesn't have to be right next to the toilet, so you have more tank location choices than you realize. However, you'd need at least a 40 gallon tank to last 4 people 5 days without a pumpout...finding a good location for a tank that big could be a challenge. If you'd like brainstorm your options, you're welcome to give me a shout via a PM to arrange a time to discuss 'em.

Btw, I see you joined our merry band only a couple of weeks ago...welcome aboard!
 
Mar 24, 2013
28
Beneteau 311 Middle River
I have a B311 and also find the holding tank restricts the time my wife and I can spend between pump outs. We purchased a composting head, will install this winter. No holding tank, no hoses. Just empty the liquids.excited to enjoy expanded freedom. craig
 
Dec 2, 1997
8,946
- - LIttle Rock
We purchased a composting head, will install this winter. No holding tank, no hoses. Just empty the liquids.excited to enjoy expanded freedom. craig
Of course there's a "holding tank" for the solids...it's just not separate from the toilet. No hoses, but you will have to find room to store the dry material (typically peat moss) and the bio-accelerator. It also needs a continuous supply of air and heat, which require power...And how do you plan to dispose of the solids?

A live-aboard couple typically has to empty the solids every two-three weeks, which is less than half the time needed to turn them into compost. Weekend warriors can give it more time, but if allowed to sit and compact, those solids can get very nasty....so you have to do a little mixing when you add the peat moss. You can't just turn off the power to it when you leave the boat either.

My point being...so-called "composters" (which are actually desiccators) aren't quite as maintenance-free as you think. So I'd do a little more research into what's actually required to keep one working and trouble free before buying one.
 
  • Like
Likes: Justin_NSA
Mar 24, 2013
28
Beneteau 311 Middle River
I expressed myself poorly, I should have said there is no holding tank to pump out or to force us to find a marina every 2-3 days. Since we don't live aboard we can deal with the solids at our convenience. One of the things we enjoy about our 9-10 day cruises around the Cheasapeake is the lack of agenda, not being obligated to frequent pump outs allows us to follow the wind and our whims. We did research various makes, most do require at air supply, C head does not. Being skeptical I didn't think it would be effective but after talking to someone who is a live aboard that uses one and smelling his head we felt comfortable enough to try one. For us, being forced to pump out frequently limited the flexibility we value.
 
Dec 2, 1997
8,946
- - LIttle Rock
I just checked out the C-Head specs. "The solid waste collection container will hold on average about 10-12 uses which will require emptying about once a week for a couple using it
daily."

Fwiw, the average adult uses the toilet 5x/24 hours. For most people 4 of those uses are only urine, which has to be collected separately AND taken ashore to be disposed of legally unless you're in open sea at least 3 miles from the nearest point on the whole US coastline. Iow, there's nowhere on the Bay where it's legal to dump it over the side. 10-12 solids deposits is 5-6/person for a couple...iow, about 3 days. I'm not seeing any advantage over an 18 gallon holding tank...and I'd bet we can find a good location for a larger one. However, there is a much better--albeit more expensive--alternative to a larger holding tank or the C-Head: a treatment device.

You're prob'ly not aware that the Chesapeake Bay is NOT "no discharge"...in fact there's only one NDZ on the whole Bay: a small harbor, Herring Bay. Which means that the discharge from a USCG Certified Type I MSD (treatment device) is legal everywhere else. Check out the Raritan PuraSan: Raritan PuraSan Promo Sheet Never have to find a pumpout again unless you visit Herring Bay.
 
Oct 3, 2008
325
Beneteau 393 Chesapeake Bay
Most US made Beneteaus, including the 381, should have a 22 gal holding tank installed vertically behind the toilet. You mentioned that space is available. There should have been attachment points in there. I am guessing that a previous owner removed it, OR, it was built in France where they sometimes install a small "harbor tank".