Replacement toliet trailer sailor w/ pump-out?

[Spot]

Hello One and All-
I need to replace the MSD III in my trailer sailor for occasional use.
Current unit is severely cracked and not holding anything liquid.
It is circa 1978 according to the small plain label with a closed lid height of 14.5" and stationed at the front edge of the v-berth. I did not see a manufacturer's name on the unit.

It is...it was...a porta-potty style unit but looks to be factory 'ready' for remote pump-out complete with the hoses and fittings going to the deck of the boat.


Does such units still exist?
Preferred makes and models?

Any types of these units to avoid?


Thanks!

[Sailmonkey]

Here ya go

https://www.thetford.com/product/porta-potti-550p/

[peghall]

You want the 550P MSD The "MSD" designation in the model name or number means it's the pumpout version. Also check out the Dometic/SeaLand 975MSD. Defender has both.


Thetford 550P MSD on Defender
SeaLand SaniPottie 975 MSD


--Peggie

[Spot]

Thanks for the replies!

To use the taller ones I would need to remodel the v-berth, which is possible as it is currently gone.

If I used a shorter one I would have to 'raise' it and only get 1/2 the tank volume.

Thetford 550P MSD Marine Porta-Potti Portable Toilet
Includes MSD (Pump-Out) Fitting and Hold Down Kit
water tank">Fresh Water Tank: 4.0 Gallons, Waste Water Tank: 5.5 Gallons
Dimensions: 16-1/2" H x 15" W x 16-1/2" D

*according to Thetford, Porta Potti® 550P This model is no longer in production and has been replaced by Porta Potti 365 w/ no mention of MSD kit*

Dometic SaniPottie 975MSD Toilet with MSD Fittings
Waste Capacity: 5.0 Gallons, Select Color
Dimensions: 15-1/4" H x 13-1/8" W x 15-1/4" D
Includes Mounting Brackets and MSD Fittings for Waste Tank Pump-Out

Dometic SaniPottie 974 Toilet with MSD fittings
Waste Capacity: 2.6 Gallons, Select Color
Dimensions: 12-1/2" H x 13-1/8" W x 15-1/4" D
Includes Mounting Brackets

[alansmith]

Is there enough room to put a composting/dedicating type of toilet in there? I think they are slit more practical for trailer sailors I own two trailerable boats. One las a Lavac and the other a C head composter.

[kclancy]

We have a Thetford. We keep it in the V-berth, but use it in the cockpit. It's decent. We went with the larger model but it's too tall to be able to use in the V-berth. We sleep in the main cabin area otherwise it would be used there. We are too tall to fit in the V-berth. Our next boat will be one we can fit in!

[peghall]

To use the taller ones I would need to remodel the v-berth, which is possible as it is currently gone. If I used a shorter one I would have to 'raise' it and only get 1/2 the tank volume.

It really needs to lie backed up to the hull 'cuz the pumpout and vent lines should be as short and straigh as possible. You've said there's already a deck pumpout fitting...what's directly below it in the cabin?



And oh, btw...if it's a little tall to go under a v-berth or settee cushion, removing the lid solves that problem. The cushion creates enough cover for it.


--Peggie

[Lake-Effect]

We replaced the original MSD III unit in our little boat with the small Thetford MSD, and it's been dependable. It has enough tank for a couple to be out for 3 or 4 days. Longer if you swim daily

[Spot]

Thanks Everyone!

@kclancy, tall sailor small boat here too, keeping it 'portable' could be useful
@alansmith, composting could also be an option, thanks
@lake-effect, thanks for the review and warning
@peghall, the pumpout lines are relatively long and in a s-bend, getting close to 7-8 feet. One could argue that there is more hose than tank in this system.

Enclosing some pics. Currently interior is stripped to hull.

[peghall]

@peghall, the pumpout lines are relatively long and in a s-bend, getting close to 7-8 feet. One could argue that there is more hose than tank in this system.

But that's the existing system. You certainly don't have to duplicate it! The pumpout line might be a bit long, but not a problem...and the vent line can be pretty short..thru-hull can be anywhere in the hull, even directly above the potty.


Otoh, you might be better off settling for the 2-3 gallon portable version on this boat...upgrade to the pumpable version when you upsize to 25'.


-Peggie

[Spot]

Originally Posted by peghall

Otoh, you might be better off settling for the 2-3 gallon portable version on this boat...upgrade to the pumpable version when you upsize to 25'.
-Peggie

Thanks Peggie. This sounds like a good plan-small boat, small 'facilities'.

Along with the big-boat 'head' plumbing, there is also a 'galley' sink going to a through-hull near the waterline without a seacock.

I am thinking I should either add a valve, or more in line with scale of the boat, close off the through-hull and catch the sink drain water in a bucket.

[peghall]

If you want to keep the sink, I'd put a seacock on the drain thru-hull. But keep in mind, you'll need a source of water to put IN the sink...either from a water tank or maybe a sea water foot pump or jugs of water. You might want to just stick with paper plates and utensils you can bring home to wash.



--Peggie

[Spot]

There is a jug with a tube leading to a manual hand pump for the sink, maybe 2 or 3 gallons. I was thinking of cleaning that all up and putting it back in the boat.

[peghall]

Good idea! If you have the space for it, consider "upgrading" the jug to 5 gals.

[NorthCoastJoe]

I ripped out all the plumbing and tank on my boat, capped off 2 thru hulls and went with a tall porta potty. Its is easy enough to carry out and dump into a toilet. Comes with a hold down kit very easy to install. I have used this on both my MacGregor 25 and Pearson 30. Very happy with it. No stinking hoses or 30 gallon tank full of you know what.

I think around $140 for it at West Marine, thetford--porta-potti 5 gallon holding tank.