Ammonia smell in cabin

[Thomas1985]

We looked at a boat that was really well kept. Cabin smelled very strongly like a cat litter box.

Any idea what would cause this kind of smell in a cabin?

[brazenarticle]

Maybe a cat?

[boatpoker]

Ever smelled a battery going into meltdown ?

[Thomas1985]

I went ahead and asked… just felt bad “why’s your boat smell like cat piss?” Really nice boat.

No I have not smelled a battery failing?

[boatpoker]

Originally Posted by Thomas1985

I went ahead and asked… just felt bad “why’s your boat smell like cat piss?” Really nice boat.

No I have not smelled a battery failing?

Stick your nose in there and sniff. Look for swollen sides of the battery cases.
It can be really bad if they explode.

[Thomas1985]

Not my boat (at least yet) so I can’t.

Does it smell like a litter box? This smelled just like a cat had been shut there.

[JPA Cate]

The fabrics in the boat can absorb that cat littler smell, or diesel, for that matter.

Be careful, sniffing, [only allow yourself a tiny sniff] because there are other gases coming out if the battery is starting to melt down, some of them very bad for you. Top priority is to get the battery off the boat and onto a dock or concrete somewhere, don't want it catching fire and burning or sinking the boat, either.

Ann

[Zanshin]

A melting or overheated battery will be leaking sulfuric acid fumes, this acrid smell is nasty (formula H2SO4, and potentially dangerous) but is distinct from ammonia (Formula NH3). The sulphur component in dilute sulfuric acid lets it smell a bit like rotten eggs (formula H2S)

So if you are fairly certain that this is not just a nasty smell that you can't identify, but ammonia, then the source is probably not the batteries. Unfortunately, it is probably urine... unless they decided to clean the boat just prior to your visit and dumped some ammonia in the bilge.

[Thomas1985]

Definitely no fart or rotten egg smell. I spent the whole time in the boat thinking about cats. Smelled just like a dirty litter box.

Maybe it is just cats 🤷🏻*♂️

[sailorboy1]

Originally Posted by Thomas1985

We looked at a boat that was really well kept. Cabin smelled very strongly like a cat litter box.

Any idea what would cause this kind of smell in a cabin?

90+% it is head hoses needing replacing

[aberglas]

Sea water that is stagnant in pipes for a while smells really bad on first flush of toilet.

[wholybee]

Ammonia or urine is a pretty distinct smell. It is different from sewage, a smelly head, or a smelly bilge. And as mentioned, a battery would smell like rotten eggs/sulfur.

Cats are very common on boats, and cat (and dog) owners rarely realize how awful they smell. It is certainly possible a cat was on board. You can see urine stains for months afterwards with an ultraviolet light. I have a UV light I have used in a rental to find stains. There are active biological cleaners that will remove them, but it's a lot of work.

It could be human urine, if the head wasn't cleaned often/well. But in that case I would think the overall appearance of the head would be a giveaway.

[Thomas1985]

Fresh water boat. They just replied there is no smell.

Maybe it’s a fluke winter storage occurrence. We did open a boat that I think had been shut for quite a while. Very clean inside.

I’m going to assume holding tank though… how hard is hose replacement if that’s the case?

[Thomas1985]

It seriously smelled distinctly like a cat litter box though.

Not like ammonia cleaner or human sewage. Like a litter box that needed emptied.

[wholybee]

If they say there is no smell but you smell it, that means they got used to it and can't smell it anymore. That sounds typical of a pet owner.