Anonymous wrote:

No limber holes; are you sure?

I have looked up the word limber and believe limber holes mean holes leading liquid into the bilge?  In that is right, the answer is no.  The volume under the cabin floor that was filled up, has its lowest point about 0,5 metre higher than the bottom of the bilge, so if there were a hole out from under the cabin, the liquid would be drained out to the slope under the engine and from there it would fall down into the bilge.

Hi Tony,

Yes, I am in Norway (Trondheim).  And yes, I agree that it must be diesel with some other stuff dissolved into it.  In  fact, the odour has been there for some years but has not been unlike the smell of diesel and oils that is quite normal in older boats.  This autumn it has become unbearable, though.  And the stench sits in clothes even after a shorter visit in the boat and it does not go away after normal laundring.

The time when the ball valve was leaking is some years ago now, but there is an opening on the top of the tank for breathing air in and for potential overflow.  A hose leads diesel overflow to the inside of the motor room below the tank.  Therefore some overflow diesel may have come from the tank as late as this summer when I had filled the tank too full and then the boat has been heeling during sailing, without me noticing it.

However, there is no direct path from a diesel pool below the tank to the cabin, so I believe the diesel must have migrated through the gelcoat and fibreglass hull, either through the vertical wall or down and forward through the fibreglass.

Thanks for the suggestions.  I think antrifreeze can be ruled out (wrong smell, no indication of leak).  Diesel:  More likely, but the timing is strange.  The overflow under the cabin comes years after I had a ball valve under the diesel tank whee it dripped from its stem.  And how the diesel has moved from there to under the cabin is unclear to me.

Anonymous wrote:

I would like to hear if anyone has experienced a phenomenon which so far is a mystery to me.  Sorry if the description of the problem seems lengthy.

There has been a strong smell in my boat the last months.  It has been there to a lesser degree for years, but now the smell has become really awful.

One day I found the carpet on the floor in the cabin soaked in a greenish liquid, although I had not spilled any liquid there.  I threw the carpet out, and started scooping up the liquid when it showed that the volume under the cabin floor was partly filled up by this liquid, to such an extent that the boat’s rolling and pitching must have made the liquid flow up through openings in the cabin floor.

The volume under the cabin floor is above and behind a 400 kg keel ballast body cast in concrete, and there is a vertical wall (a small «bulkhead») separating this volume from the motor room placed under the deck aft of the cabin.  There is no way arranged to drain this volume into the bilge under the motor room.  I peeked through a hole in the cabin floor and saw a liquid surface quite high up in there, and I then pumped out between two and three litres, (see photo of the bucket).

The smell is like that of a strange mix of diesel, white spirit and oil-based paint, and the liquid feels more viscous than diesel, more like motor oil.  I must use rubber gloves next time, as my hands keep a smell of this aggressive chemical a couple of days.

The green colour is  quite similar to that of the diesel sold in Norway for boats and tractors (coloured so it can be distinguished from the more heavily taxed diesel for road vehicles).

The mystery to me is, what is this liquid.  I am sure I have not messed with diesel, nor white spirit or any other fluid there. 

The boat is made in GRP and is old, about 45 years, and has had blisters at the waterline up through the years.  In 2018 there were a lot.  I drilled small holes at the blisters and filled these with epoxy resin, then coated with gelcoat and antifouling.  Since then (April 2018) the boat has been on the water all the time (moored in brackish where there is almost no barnacle growth).

Could this liquid be a reaction product from plastics and intruded seawater, and the liquid has moved through the GRP to the inside and accumulated there?  I have looked into articles about blisters, but can’t find anything to support this idea.  Chemistry is not my field, though. 

An article, of many: 

http://www.smithandcompany.org/GRP/GRP.html

Any explanation, anyone?

The green colour put me in mind of antifreeze. Check hoses?

I would like to hear if anyone has experienced a phenomenon which so far is a mystery to me.  Sorry if the description of the problem seems lengthy.

There has been a strong smell in my boat the last months.  It has been there to a lesser degree for years, but now the smell has become really awful.

One day I found the carpet on the floor in the cabin soaked in a greenish liquid, although I had not spilled any liquid there.  I threw the carpet out, and started scooping up the liquid when it showed that the volume under the cabin floor was partly filled up by this liquid, to such an extent that the boat’s rolling and pitching must have made the liquid flow up through openings in the cabin floor.

The volume under the cabin floor is above and behind a 400 kg keel ballast body cast in concrete, and there is a vertical wall (a small «bulkhead») separating this volume from the motor room placed under the deck aft of the cabin.  There is no way arranged to drain this volume into the bilge under the motor room.  I peeked through a hole in the cabin floor and saw a liquid surface quite high up in there, and I then pumped out between two and three litres, (see photo of the bucket).

The smell is like that of a strange mix of diesel, white spirit and oil-based paint, and the liquid feels more viscous than diesel, more like motor oil.  I must use rubber gloves next time, as my hands keep a smell of this aggressive chemical a couple of days.

The green colour is  quite similar to that of the diesel sold in Norway for boats and tractors (coloured so it can be distinguished from the more heavily taxed diesel for road vehicles).

The mystery to me is, what is this liquid.  I am sure I have not messed with diesel, nor white spirit or any other fluid there. 

The boat is made in GRP and is old, about 45 years, and has had blisters at the waterline up through the years.  In 2018 there were a lot.  I drilled small holes at the blisters and filled these with epoxy resin, then coated with gelcoat and antifouling.  Since then (April 2018) the boat has been on the water all the time (moored in brackish where there is almost no barnacle growth).

Could this liquid be a reaction product from plastics and intruded seawater, and the liquid has moved through the GRP to the inside and accumulated there?  I have looked into articles about blisters, but can’t find anything to support this idea.  Chemistry is not my field, though. 

An article, of many: 

http://www.smithandcompany.org/GRP/GRP.html

Any explanation, anyone?