Toilet Options for 31 Footer

[alanfw]

I’m considering toilet options for my 31ft yacht (which I bought 16 months ago). Currently it has a macerator toilet with no holding tank which limits where it can be used legally. I plan on keeping the boat for a few more years, with the intention of completing a full Queensland coastal cruise when my partner retires. With this plan in mind, I don’t think the current set-up is suitable. I’d like to hear feedback on the various options to choose from.

1. Keep the current toilet and carry a “porta-potti”. We already have one of these for our camper trailer, and HAVE taken it with us on overnight Bay sails. The head area (which includes wardrobe and wet locker) is between the saloon and V-berth and is not spacious so the porta-potti is somewhat in the way, but it works. On longer sails, could the porta-potti be emptied into the macerator toilet?
2. Install an all-in-one toilet and holding tank like the Dometic 711-M28. https://www.dometic.com/en-ca/outdoo...ic-711-_-25364
   I assume I could use the existing plumbing to empty and flush the tank where legal to do so, but I would have to add a vent.
3. Install a cassette toilet like those used in RVs - eg Saneo. I don’t know for sure but it appears these all require access to the rear of the toilet to remove the cassette, which doesn’t seem possible. I’m also not sure but I think I would need to install a vent for this as well.
4. Install a composting toilet? From what I’ve read, these need more volume capacity than most holding tanks, so not sure I have the space for one of these.

If you any helpful experience I'd really appreciate your input. If it helps, here is the current installation:


Cheers

Alan

[HTurner]

Why not add a small holding tank such as:


https://www.defender.com/product3.js...300&id=828013#

[JPA Cate]

For the PortaPotti to be a reasonable option, you'd have to access the sea for running the excreta through the macerator and out to finish the dilution process. If where you envision going in Qld is up into all the protected areas (rivers and inside barrier islands), I'm wondering what quantity of excreta the PP can handle? All small holding tanks require frequent sucking out. You'd probably wind up having to go into marinas to do that, unless you go frequently out into the Pacific and the Coral Sea. My answer partly depends on how you plan to schedule your cruising. If you do add a holding tank to your boat, think long and hard about how you are going to flush it, lest it become clogged with desiccated effluent. Do not rely on "Y" valves, but on double hoses with ball valves. The Y valves handle break easily, and they clog easily. Imo, they are a curse to be avoided. It will make the plumbing more difficult because space is so limited on 30 ft. boats.

You may decide you don't have room for a holding tank, which may mean that you will have to plan your trips around going where it is legal to pump out.

I understand that packages of coir for the desiccating toilets are now available in Australia. I don't think there are laws regarding the disposal of the used coir, as yet. And, of course the urine is easily disposed of here. If you are interested in the desiccating toilets, search (CF Custom Google Search) on desiccating toilets, plus Mike OReilly. He is a Canadian CF member who has written a lot about he and his wife's usage of theirs.


Ann

[dlj]

I go for an OGO composting head. Very nice product, nice footprint, fits well in small spaces.

dj

[alanfw]

Originally Posted by dlj

I go for an OGO composting head. Very nice product, nice footprint, fits well in small spaces.

dj

That looks very interesting! Will need to do some measuring.
Thanks

[Ratel]

I will also recommend the OGO.

We are putting 2 of them in our Seaquest 46. OGO is a well designed product that works as advertised. Very good customer service too.

We actually trialed one in our house exclusively for 10 days, just to make sure. Without venting outside there was zero smell from the solids compartment (even when emptying it.) We used Coco choir.

The only objectionable smell will be when you empty the urine container, that is over in less than a minute.

[goboatingnow]

Just fit a small tank and a overboard exit

[Fore and Aft]

Alanfw I am with GBN, I reckon with a bit of modification you could fit one behind the toilet. If you keep it up high enough, you could use gravity to empty it through a seacock at the bottom. We have our holding tank set up, so all the waste goes through it and straight out the bottom. We turn the outlet seacock off when beached or in areas where you can't have waste.
I see the OGO has a 9-litre urine bottle so as long as you don't have to many people or cups of tea onboard that should last for four days until then what? You decant it into a 20-litre jerry jug to responsibly dispose of onshore along with the solids? Or do you tip it over the side?
I am not a composting toilet fan on boats. At home we have a Clivus Multrum composting toilet that does what it says. Composts waste, so when I do the yearly empty at home all I have is a black soil looking substance.
Cheers

[dlj]

I bought an extra urine bottle so that when I have to pull it out the full one, I simply cap it and put the empty one in the unit. So no decanting... Having two urine bottles has worked well for me. Four days is about right per bottle by the way. That's with two people on board.

I understand the concern about once things are full, but with a small holding tank as one would have on a small sailboat, you have the same concern.

Honestly, after putting in this OGO, it has been the simplest, most stress free system I've ever used on a boat. I've been frankly surprised. No looking for and paying for pump-outs, no looking to see if I can discharge overboard, no smells, no hassles.

I guess the only hassle is I did have one guest that found always sitting for #1 was not to his liking. He said he could get used to it, but he was not too comfortable with it.

I also like to keep it clean. When using it for #1, I wipe the area with toilet paper and frequently use a spray product that helps keep things both clean and nice smelling. It had been suggested to me to use "Bio-Enzymatic Urine Digester with Odor Neutralizer by Nilodor, Original". I really like that product.

Clivus Multrum - one of the original compositing designs. I remember when we were building them for folks living off-grid back in the '70's. I don't know where you have your system, but at least in the area where we were doing those, there were some mighty gnarly looking bugs that would live in them, made you wonder about sitting down to use them...

dj

[rslifkin]

If you have room for a tank, I see no reason you couldn't just add a tank while keeping the existing toilet if it works well.

[alanfw]

Thankyou everyone for the input. I really don't think a separate holding tank is viable - there just doesn't seem to be enough space for a practically sized one. Like the look of the OGO - what I have learnt so far it seems great. I haven't measured yet though. My only concern is cost - am I over-capitalising spending $2,500 on a head when the whole boat cost $35,000? And would the OGO be a selling point or a turn-off for buyers in this budget?

[Mike OReilly]

Go for a composter. OGO looks good. I have a Nature’s Head, but it may be too large for your boat.

For some future buyers, a composter will be a positive aspect. Some might see it as a negative. This is true for all aspects of any boat. I say, get what you need, not what some hypothetical future buyer might want.

[peghall]

The Dometic 711-M28 has always been one of my favorite systems. However, its 20" x 20" tank footprint may be a deal breaker 'cuz not many heads are big enough for it.


There is much less elegant version of it: an MSD portapotty. The "MSD" designation in the model name/number means it has fittings for a pumpout line and vent line, and is designed to be permanently installed (actually just sturdier brackets than portables, so you could still take it off the boat if you absolutely have to), which means that although it's still called a PORTApotty, you don't have to carry anything off the boat to empty it.

A 5-6 gallon model is household height and holds 50-60 flushes...you'd need at least a 30 gal tank to hold that many from a manual marine toilet. No plumbing needed except a vent line and pumpout hose--so no new holes in the boat with the possible exception of a deck pumpout fitting and a vent thru-hull unless you want to be able to dump it at sea, in which case you'll need a y-valve in the pumpout line, a manual or electric overboard discharge pump and a another slight larger thru-hull--preferably below waterline...and -0- maintenance needed except for rinsing out the tank--which you can do with a bucket while it's being pumped out. Total cost including the pumpout hose and vent line is about $300--a fraction of what you'd spend for toilet, tank and all the related plumbing needed. And the best part is, you have all the advantages of a toilet and holding tank without giving up a single square foot of storage space.

If this idea appeals to you, check out the Dometic/SeaLand 975MSD Defender has it for the best price and their listing provides the most information.
Dometic SaniPottie 975MSD Toilet with MSD Fittings - Gray | Defender Marine


--Peggie

[Fore and Aft]

Alanfw how about a bulkhead mounted holding tank and Y Valve. Not hard to install and you can still keep using the electric toilet. Plenty of yachts I survey have bulkhead mounted holding tanks. More than one looks like they have never been used.
Cheers

https://marine4x4supastore.com.au/pr...ste-water-tank
https://www.keoghsmarine.com.au/PLUM...roduct_id=7318