Adding a Marine Head

Tedd

.
Jul 25, 2013
745
TES 246 Versus near Vancouver, BC
Some of the 26RKs I've looked at have a port-a-potty. A marine head is a "must" on my requirements list. Roughly how much would it cost to add one? I have the original options list and it quotes $375 for the marine head option, but I assume it would cost me more to add one after the fact.
 
Nov 22, 2011
1,192
Ericson 26-2 San Pedro, CA
Some of the 26RKs I've looked at have a port-a-potty. A marine head is a "must" on my requirements list. Roughly how much would it cost to add one? I have the original options list and it quotes $375 for the marine head option, but I assume it would cost me more to add one after the fact.
I think the best option for a boat your size (and my size--an Ericson 26) is an MSD porta potty. This has a built-in tank that can be plumbed for overboard discharge through a macerator and/or deck pump out. Because of the miniscule amount of flush water used, it will give you the equivalent capacity to a ~20 gal. conventional tank and take up a good deal less space.

My boat has a Thetford 550p MSD. Though you can find them still, I believe this model has been discontinued, but there are other similar models out there.

I've had boats with both conventional holding tank setups and can say that I really like the MSD porta potty. It really makes sense for a boat our size. Plus, installation will be much simpler for you. The only caveat I'd add is that the plastic hold down brackets--for the Thetford, at any rate--were rather flimsy, so I replaced them with custom-fabricated stainless ones. I did not want 5 gal. of crap flying around the boat if the weather got rough! :yikes:
 
  • Like
Likes: tfox2069

Tedd

.
Jul 25, 2013
745
TES 246 Versus near Vancouver, BC
@Alan Gomes :

Great tip, thanks very much! That does look like an excellent option if I find a boat I like that doesn't already have a marine toilet.

Know what you mean about brackets. I had one of the bowl-to-tank brackets fail on my port-a-pottie and woke up to--let's just call it flooding--on the floor. I definitely don't want to face that again!

Tedd
 
Dec 2, 1997
8,710
- - LIttle Rock
+1 for an MSD portapotty...here are all the reasons why:

On any boat much smaller than about 30', a self-contained system—an "MSD" portapotty-- makes a lot of sense. 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 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...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 $200--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.

Thetford has discontinued the 550P MSD, but you may still be able to find it at some retailers. The Dometic/SeaLand 975 is the only MSD portapotty still in production in the US...however most of 'em are comparable to each other, so just pay close attention to details like height and features.

--Peggie
 
  • Helpful
Likes: tfox2069
Nov 22, 2011
1,192
Ericson 26-2 San Pedro, CA
+1 for an MSD portapotty...here are all the reasons why:

On any boat much smaller than about 30', a self-contained system—an "MSD" portapotty-- makes a lot of sense. 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 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...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 $200--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.

Thetford has discontinued the 550P MSD, but you may still be able to find it at some retailers. The Dometic/SeaLand 975 is the only MSD portapotty still in production in the US...however most of 'em are comparable to each other, so just pay close attention to details like height and features.

--Peggie
I agree with almost everything you said there, Peggy--obviously, since I went the MSD portapotty route based on your recommendation! The only thing I would point out is that those "sturdier brackets"--on the Thetford, at least--were a complete joke. They are cheap plastic and can flex, with potentially very ugly results! Other than that, I've been totally happy with this setup.

One other nice feature is that I *can* remove the whole thing and take it home for a deep cleaning if I want to. I've done that one time when the tank built up some calcified crud in it. It was a very easy matter to remove it from the boat and take it home to work on.

Oh, and another point to mention (which you have commented on in the past): the porta potty is so simple because there's nothing to maintain in terms of rebuilding pumps, joker valves, etc. Very, very reliable.
 
Nov 8, 2007
1,523
Hunter 27_75-84 Sandusky Harbor Marina, Ohio
For all the reasons above, we prefer our MSD on our boat. It’s our 21st season with it, and is simply easier and better than the marine toilets on our 15 charters over the same time period.
 
  • Like
Likes: Alan Gomes

Tedd

.
Jul 25, 2013
745
TES 246 Versus near Vancouver, BC
This is all great information. Thanks very much everyone.
 
Jul 1, 2010
962
Catalina 350 Lake Huron
One other option is a composting head. I replaced the Jabsco manual marine head with a
C-head on our Seaward 25. It was a major improvement for us. The small 10 gal. tank on the marine head on the Seaward doesn't get you far between pumpouts.
 
Feb 8, 2014
1,300
Columbia 36 Muskegon
We're going to the C-Head composting toilet this Fall. Solid waste gets tossed into any dumpster, perfectly legal, and liquid can be retained till you can dump it in a restroom. There's another option for that that I'm sure most people use, but since it's not technically legal in many places I won't go there. I think you can guess what I mean. The liquid goes into a regular gallon milk jug so spares are basically free. Everything I've read or seen about them says there's no odor as long as you empty it often enough, and that's at least a week or two for two people for the solids tank. I can barely do that with my holding tank system and then I have to find a pump out station, which in some places can be tough.
 
Jul 1, 2010
962
Catalina 350 Lake Huron
We generally get a week on ours before we dump it. Sandy (the c-head guy) used to include a venting cover with the c-head so you could put a 5 gal storage bucket vented in line with the head. With that setup we can go a month before we have to dump it. Not sure if he still includes that with the new c-heads.
 
Jul 30, 2019
216
Seaward 25 777 Fort St. James
But..... the easiest and cheapest thing to do on a boat is to go with what is already there.

If it is a marine head and holding tank, so long as you have access to a pumpout and are not taking long trips where there are no pumpouts, then a Jabsco-style head is just fine. Like using a "real" toilet, hygienic, no smell if well maintained.

And if changing the joker valve (and base valve, since you might as well) as I did a couple of weeks ago is the worst job, then I wouldn't worry, since changing both valves took me less time than a single emptying of a composting toilet in any of the numerous videos that are touting them, somewhat unconvincingly, to me at least. And those valves last several years before replacement is needed. If you can find a single one of those videos where the people don't look as if this is a really unpleasant experience that they are making the best of, please tell me how to find it.
 
Dec 2, 1997
8,710
- - LIttle Rock
Joker valves should be replaced at least annually if you want your toilet to continue working anywhere near factory specs.

(excerpt from my book)
Most people think that the only thing the joker valve does is acts as a check valve to stop backflow from returning to the toilet or odor from the tank from escaping through the toilet. But that's the joker valve's LEAST important function...in fact, the joker valve is THE single most important replaceable part in a manual toilet.

Here's why:
On the upstroke of the piston, a vacuum is created in the area beneath the piston. This causes the joker valve to close tightly, and the flapper valve beneath the pump to open, allowing some of the contents of the toilet bowl to be drawn into the bottom half of the pump. Then, on the down stroke of the piston, the flapper valve is slammed shut, and the effluent is forced out of the bottom of the pump, through the joker valve, and off down the line. But when the joker valve becomes more and more worn and/or there's a buildup of sea water minerals on it, it can no longer seal tightly on the upstroke of the piston so less and less vacuum is created, requiring more and more pumping to move bowl contents.

You prob'ly won't notice the loss of efficiency at first because it's so gradual. But I guarantee you that if it's been two years or longer since you replaced the joker valve, you need to pump the toilet at least 50% more times to move the bowl contents to the tank or all the way out the thru-hull....IF they're getting there at all any more.

Replacing a joker valve doesn't have to be a nasty job...just flush a couple gallons of clean fresh water through the system before starting the job.

--Peggie
 
  • Helpful
Likes: tfox2069
Jul 1, 2010
962
Catalina 350 Lake Huron
since changing both valves took me less time than a single emptying of a composting toilet in any of the numerous videos that are touting them, somewhat unconvincingly, to me at least. And those valves last several years before replacement is needed. If you can find a single one of those videos where the people don't look as if this is a really unpleasant experience that they are making the best of, please tell me how to find it.
You've obviously never used one :) . Don't get me wrong, marine heads have their place too. I love the electric head on our Catalina 350. It's a well designed system and works well. On the Seaward though, I'd never go back to the marine head from the C-head composter that we put in it.
 
Jul 30, 2019
216
Seaward 25 777 Fort St. James
You've obviously never used one :) . Don't get me wrong, marine heads have their place too. I love the electric head on our Catalina 350. It's a well designed system and works well. On the Seaward though, I'd never go back to the marine head from the C-head composter that we put in it.
It is true enough, I have not, either used one or emptied one. I like the idea of a composting toilet, in a cabin in the woods for instance. In an RV they may well also be practical, but I have some problems with them in a boat. First of all is the means of disposal: finding someone else's garbage seems popular, or possibly landing on a quiet shore and sprinkling the contents in bushes? Let's face it, this is fecal matter, not harmless humus. Given long enough it will indeed compost down to something like soil, but not if you are emptying it every week! There will be lumps in it, those lumps are turds, and putting human stools in the garbage or leaving them lying around in woodland, would be distinctly unsanitary. In a land-based set up, with a large container and months between emptying, you produce harmless humus, and in an RV, you could pay for a dump station and tip the contents down into the dump tank, but neither is the case on a boat. Finally, in a rolling, pitching, yawing boat, none of the urine collection methods I have seen appears proof against occasional spillage, and we all know that a dirty toilet smells above all of stale urine, which is a most penetrating, unmistakable and stubbornly persistent odor.

PS: As an addendum, I was surprised to find that the common composting toilets cannot accept toilet paper. So you have to have another little container filling with soiled toilet paper! And that doesn't smell?
 
Last edited:
Jul 1, 2010
962
Catalina 350 Lake Huron
When it comes to boats there is no ideal solution for human waste. Ideally, it would just disappear to poop wasteland like it does in a house, but with every marine solution, be it a marine toilet, porta pottie, wag bags, composter, or just a 5 gal bucket there is some degree of getting intimate with your own waste and maintaining and cleaning whatever solution you've chosen.

For the compster, it's really no big deal. Nothing to maintain. A spritz of vinegar water keeps it clean and odor free. Nothing ever gets spilled. No clogs to worry about. As I mentioned above, we can go a month without having to dump the compost bin, so I've always just taken it home and buried it in the yard. We do cruise our boats a lot so finding the next pump out for a tank that is on the small side is a concern for us. The only real issue with composters is what to do with the urine. Also not a huge deal as the C-head uses 1 gal milk jugs. We keep 3 on hand and store it until we can dump it in a bathroom toilet or somewhere on land when we're in more remote places.

I did just throw out the composter idea for the OP as another alternative he may not have considered. I think he's also the guy that was asking about a way to dump a marine head into an RV dump station. This would be a non-issue with a composter. We've camped in the boat when traveling with it on the trailer and used the composting head on land. (Can't do that with a marine head ). Certainly not for everyone but we've been happy with ours. We also pull it out of the boat and use it in our cabin. It's a good solution for our off grid cabin too.
 
Sep 22, 2019
118
Chrysler 26 Pymatuning Lake
+1 for an MSD portapotty...here are all the reasons why:

On any boat much smaller than about 30', a self-contained system—an "MSD" portapotty-- makes a lot of sense. 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 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...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 $200--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.

Thetford has discontinued the 550P MSD, but you may still be able to find it at some retailers. The Dometic/SeaLand 975 is the only MSD portapotty still in production in the US...however most of 'em are comparable to each other, so just pay close attention to details like height and features.

--Peggie
I take it you would recommend a MSD porta potty for a30 ft sailboat as well?
 
Dec 2, 1997
8,710
- - LIttle Rock
The target market for MSD portapotties is smaller boats because they offer everything a marine toilet and holding tank does, but without giving up a single cubic foot of the very limited amount of storage space needed for a tank and all the related plumbing and for a lot less money. However I've known several owners of 30'+ boats who went with an MSD portapotty as an inexpensive way to have a working system during the 2-3 years they were spending restoring a "project" boat, and liked it so much that they just kept it after all the work was done instead of "upgrading" to a traditional toilet and tank system.

--Peggie
 
  • Like
Likes: Alan Gomes
Sep 22, 2019
118
Chrysler 26 Pymatuning Lake
The target market for MSD portapotties is smaller boats because they offer everything a marine toilet and holding tank does, but without giving up a single cubic foot of the very limited amount of storage space needed for a tank and all the related plumbing and for a lot less money. However I've known several owners of 30'+ boats who went with an MSD portapotty as an inexpensive way to have a working system during the 2-3 years they were spending restoring a "project" boat, and liked it so much that they just kept it after all the work was done instead of "upgrading" to a traditional toilet and tank system.

--Peggie
Awesome! Do you recommend the thetdford 550p or the dometic 975 ?
 
Dec 2, 1997
8,710
- - LIttle Rock
Thetford discontinued the 550P (MSD version of their 550) several years ago. The Dometic 975 is the only MSD portapotty still sold in the US (or anywhere else that I know of)....fortunately excellent quality.
However if you possess any "handyman" skills at all, it's fairly easy to turn almost any portapotty into an MSD version, thanks to a li'l gizmo called the Uniseal UNISEAL

--Peggie