Are dry bilges necessary?

[MYAG]

Ok so I am in the school of “bilges should be powder dry” at all times unless you have a problem….. that’s how it is with my boat with any washdown or rain water from decks or storage lockers/bins etc; channelled by hoses to a port or stbd manifold in the engine room then routed out by gravity through a discharge fitting just above the water line. - no problem there.

However I have been interested in a US sportfish type boat around 30-40ft with outboards for a while and went over to MIBS last week to take a closer look at them. Speaking to my shortlist of brands, I asked about the drainage and was (to my surprise) told that it is quite normal practice there to drain out through the bilges (including grey water and a/c condensate for some builders), relying on the bilge pumps to discharge as the bilge level rises sufficiently or manually operating the bilge pump switch at the helm more frequently if preferred. (Admittedly this is how it is setup on my Nouvurania 430 tender for rainwater/washdown but that is a 14ft dinghy with no accommodation and almost zero freeboard.)

Would be interested to hear who else uses this method on their boats and if it works out ok in practice? Is this a US thing or are other boat builders in Europe doing similar too? I suppose it gives your bilge pumps a workout regularly if nothing else.

 

[BruceK]

My gut feel is with outboards it's more tolerable. With inboard engines I would like the bilge powder dry. Just my take FWIW.

 

[jimmy_the_builder]

Evening M

I viewed a Fairine Targa 47 near Venice at the end of last year which had the aircon condensate drain routed into the bilge, following exactly the principle that you've described. It wasn't an OE installation. The consequence was that the bilge was stained from standing water (and the boat was full of mosquitoes, which may or may not have been related). Bad practice imho.

 

[[2068]]

A grey water box has a filter that can be easily removed to clear out hair etc.
I wouldn't want soapy water underneath my engines, nor grey water debris blocking my bilge pump.

 

[kashurst]

sounds a bit cheap and nasty to me. A pump out box is @ £100 - why dump it in the bilges to get smelly and sticky.

 

[GrahamHR]

It's so variable even with the same manufacturer.

Our 1999 boat had a bone dry bilge.

Our 2004 boat had a wet bilge ( fresh water)

Our 2009 boat has an equally wet bilge.

I don't like it, but finding the rain water leak is proving very difficult !

 

[CX54WEK]

I personally wouldn't want wet bilges.

All that extra moisture in the boat can't do it any favours.

ETA: Our boat has bone dry bilges unless we have a leak somewhere.

 

[Wavey]

Not keen on wet bilges tbh, although that might be partly due to the fact I owned a steel boat for 20 years.

Only come across one instance where grey water was emptied intentionally into the bilges and that was on a Carver a friend had some years back.

 

[CX54WEK]

Not keen on wet bilges tbh, although that might be partly due to the fact I owned a steel boat for 20 years.

Only come across one instance where grey water was emptied intentionally into the bilges and that was on a Carver a friend had some years back.

Seems a bit of an odd system when a sump box and pump is circa £100 and keeps the bilges dry.

 

[Wavey]

Seems a bit of an odd system when a sump box and pump is circa £100 and keeps the bilges dry.

Agreed, but I always got the impression the boat was built down to a price and pennies were saved wherever possible. Not a boat built with longevity in mind.

 

[Dick Atcherley]

I want dry bilges; firstly, having moisture in a locked boat is a bad idea. Secondly, if the bilges are usually dry and you see any water, it's nice and easy to spot that there's a problem. If your bilges are wet, how do you tell whether they are more or less wet than usual if you have automatic bilge pumps? When you get to your mooring, it may be just the 'usual' bilge-water level because the boat is watertight, or it may be the usual level because your bilge-pumps have been going for the last week, just to stay ahead, and there is a developing problem that will develop in earnest when you get mid-channel.

 

[Scubadoo]

Dry bilge for me, it seems very odd to dump water into the bilge like that. With a dry bilge you can see when you have leaks etc and if you have water always in there I would worry about my engine(s) rusting particularly the oil sump which is the bit you can't see.

 

[Deleted User YDKXO]

The consequence was that the bilge was stained from standing water (and the boat was full of mosquitoes, which may or may not have been related).

For our honeymoon, SWMBO and I chartered a trawler type mobo in the BVI. On the first night onboard, I was stung 52 times by mosquitos (she counted every one) and that was with the windows closed and the aircon on. I later discovered that all the shower and sink waste discharged straight into the bilges and collected under the aft master cabin thus forming a mosquito breeding farm directly under our honeymoon bed; she blamed me of course

 

[MYAG]

For our honeymoon, SWMBO and I chartered a trawler type mobo in the BVI. On the first night onboard, I was stung 52 times by mosquitos (she counted every one) and that was with the windows closed and the aircon on. I later discovered that all the shower and sink waste discharged straight into the bilges and collected under the aft master cabin thus forming a mosquito breeding farm directly under our honeymoon bed; she blamed me of course

Right that's enough for me, thanks to all, I will be designing the plumbing to my spec with all discharge directly overboard. The thing is, there must be many, many boats in the UK and Europe which have these wet bilges, yet I don't recall having heard these problems, albeit obvious. Go figure......

Mike, stung anywhere nasty?

 

[MYAG]

Evening M

I viewed a Fairine Targa 47 near Venice at the end of last year which had the aircon condensate drain routed into the bilge, following exactly the principle that you've described. It wasn't an OE installation. The consequence was that the bilge was stained from standing water (and the boat was full of mosquitoes, which may or may not have been related). Bad practice imho.

Afternoon J

I can handle the staining, easily cleaned if not left too long, its the mozzies that I cant handle.... cheers for the pointer.

 

[Deleted User YDKXO]

Mike, stung anywhere nasty?

Well it was a long time ago but I seem to remember that everything was still in working order despite the mosquito attack although I'm not sure I was looking at my finest with 52 pink splodges of camomile lotion on me

 

[jimmy_the_builder]

Well it was a long time ago but I seem to remember that everything was still in working order despite the mosquito attack although I'm not sure I was looking at my finest with 52 pink splodges of camomile lotion on me

 

[MYAG]

Well it was a long time ago but I seem to remember that everything was still in working order despite the mosquito attack although I'm not sure I was looking at my finest with 52 pink splodges of camomile lotion on me

Surprised you could get 52 on it......

 

[MYAG]

You could not have written the script Jimmy. Quality.

Mike, I'm still laughing. Sorry.

 

[No Regrets]

Hmmm, not always possible, but desirable IMHO.

My Scand now has dry bilges, after tweaking the shaft seals, and seeking any possible ingress of H2O from every source, and frankly, it feels good.

It's just good housekeeping...