General Info: Seawater in the bilge

[katsumi]

Originally Posted by faa50

Thanks Stu for correction on limber holes.

Good points. Some of the limber holes are accessible, others on this model are near impossible. But closing down the ones that I can get to easily is a good suggestion in order to reduce the search area.

Lagoons have saildrives - mine has the SD20. In regard to each engine room water tight - answer is yes each engine room is water tight with a large lazarret lid that design prevents water from entering. Each does have a limber hole to allow any water to drain to the bilge.

In regard to water accumulation rate - I have watched this and it seems to be a fairly slow but steady rate of buildup of water. After 4 hours of sailing/motoring the seawater will be above the bilge pump by 3-4 inches. And after draining this amount, if boat is still in motion the seawater will again build up. We've been at anchor now since Sunday PM and no water penetration at all. It makes it difficult to test for leaks when they are not leading - (DM)! Getting down in the bilge with the boat pounding through 5-7 seas is not a realistic option. Certainly we can wait until calmer waters.

Nobody is saying anythng about a seawater value siphoning in during sailing so I'm guessing my original idea is flawed.

Still seeking guidance.

Your last sentence is probably the most likely scenario, either the water is coming back through the pump if it is the submersible type, I would check this first. I am surprised you that type of pump on board. You should look for any check valves in the system and make sure they are not stuck open with hair or other foreign matter.

[barnakiel]

A cracked seacock can leak slowly for weeks or months before it bursts open. If your water is salty, make sure all seacocks are sound.

A leaking seacock is easy to tell as it tends to stain the hull with a greenish tint.

b.

[Reefmagnet]

My boat was doing exactly the same thing. In my case it was the rudder gland. The reason it leaked under motor or sail and not at rest was because the squat of the boat's rear, when moving, dropped the gland below the waterline.

[Lepke]

Check valves in a bilge pump line don't always check backflow. Properly installed pumps don't need check valves. They can be held open by the bilge debris that passes thru the pump. Same with shower sump pumps.

[cpt_757]

Originally Posted by faa50

Thanks for the tips. I don't recall seeing any lines running from the bow or transom of either hull, but will recheck to confirm. Instead we located "weep" holes on each lateral structure bulkhead support that allows water to transverse from along any point in the hull to the lowest point where the bilge is located. In our model, this a a rectangle recessed below the interior hull bottom about 14" by 18" in which the water collects. The bilge sump pump is located at the bottom of this rectangle which is approximately 12" deep.

Whatever is leaking is consistent. Wouldn't a slow leak still leak while the boat is at anchor?

For me, sounds like stuffing box. If it became loose even without engine running. Check the engine and shaft area.

[PaulinOz]

"For me, sounds like stuffing box. " Not likely on a SD20 sail drive.

Bilge pump siphoning, is there not a shutoff valve on the thru hull for the bilge pump to close to prove this?

Where does your bilge pump empty out, above or below the your water line.?

If you run your engine for an hour at anchor do you get any water ingress? (dry bilge first so you can tell) 3 to 4 inches in 4 hours should = 1 inch in a n hour.

[cpt_757]

Originally Posted by PaulinOz

"For me, sounds like stuffing box. " Not likely on a SD20 sail drive.

Bilge pump siphoning, is there not a shutoff valve on the thru hull for the bilge pump to close to prove this?

Where does your bilge pump empty out, above or below the your water line.?

If you run your engine for an hour at anchor do you get any water ingress? (dry bilge first so you can tell) 3 to 4 inches in 4 hours should = 1 inch in a n hour.

Sorry, did not know that has sail drive.

[Rustic Charm]

Just out of interest, and to narrow things down a little. Does the leak occur when your engine is OFF?

You seem to be implying it's only leaking when your out and not when sitting at the dock for example?

[boatman61]

Dry off your engine compartment and before you head out next time lay a few sheets of kitchen roll up by the fwd bulkhead by the limber hole.. could be that when under load due to motoring or sailing there's a slight leak at the gasket.. maybe something needs tightening around the saildrive thru hull.
Have had that happen in the past on a couple of mono's

[PaulMarion]

Another couple of tricky places to look, AFTER you confirm it's not leaking from engine area, (raw water pump, sea cock at base of saildrive, exhaust etc) ARE: Escape hatches. Check for water on the inside or running down from the lock handles, a very tricky one! Head inlet or exit pipes. These are generally just below the water line and if one has become unsealed, or loosened, they will dribble while underway. Both have happened on my cat over the years.

[Rustic Charm]

Another place to check is where the exhaust exits the hull. In my case I have a plastic gooseneck water lock on the hull outlet ( in addition to the engine one). I'm not sure of it's purpose, but mine leaks behind this thing. Really hard to get at. I thought I had fixed mine when I repainted, but as I discovered recently when I run the engine I'm still collecting about 20mm of water about every 4 hours.

[catstevens]

On the sea water cooling for the engine, after the sea water has gone through the engine it will go through a syphon valve. The valve allows air to enter a the line when the engine is shut down.this is to stop the water following backwards. In my case the little valve component failed, so when ever the engine was running salt water would enter the bilge.

The syphon valve is usually in the locker next to the engine, a small black tube drops the water into the bilge. Start the engine and check for any water coming out of the tube.

Any way that's what happened to me and it took ages to find.

Hope this solves the problem

Catstevens.

[faa50]

Thanks for all the comments.

I've run the two engines 3YM30 Yanmar's 30hp located in each hull about 110 hrs the past two months. Nearly half of this time is on a mooring or anchor. Both engine rooms show no water ingress, I've monitored this closely.

Since the boat is less than two years old, the seacocks should not be an issue to age, but this doesn't mean they may not be the culprit just thinking low probability. Although one seacock has a brownish stainline running from it to the bilge. Thinking this may be part of the problem. Someone earlier pointed out for me to look for this telltale sign.

I spoke with the Lagoon Dealer who sold us the boat and he was surprised to hear of us having this problem. He spoke with the owner of the Lagoon Dealership and he too was not familiar with what may be causing the problem.

I had said in an earlier post the water coming in average 3-4 inches above the bilge pump. That turns out to be an overstatement, I now believe it is more like 2-3 inches after the water fills the rectangle box the bilge pump resides in. So it is a relatively slow leak but persistent. And no it doesn't leak when the engines are running provided the boat is not moving through the water.

Its likely others have experienced a similar issue with this model and possible make of boat. We are sailing to Antigua then Grenada in the next week so I'd like to resolve this issue prior to departing.

[Rustic Charm]

Originally Posted by faa50

Thanks for all the comments.

I've run the two engines 3YM30 Yanmar's 30hp located in each hull about 110 hrs the past two months. Nearly half of this time is on a mooring or anchor. Both engine rooms show no water ingress, I've monitored this closely.

Since the boat is less than two years old, the seacocks should not be an issue to age, but this doesn't mean they may not be the culprit just thinking low probability. Although one seacock has a brownish stainline running from it to the bilge. Thinking this may be part of the problem. Someone earlier pointed out for me to look for this telltale sign.

I spoke with the Lagoon Dealer who sold us the boat and he was surprised to hear of us having this problem. He spoke with the owner of the Lagoon Dealership and he too was not familiar with what may be causing the problem.

I had said in an earlier post the water coming in average 3-4 inches above the bilge pump. That turns out to be an overstatement, I now believe it is more like 2-3 inches after the water fills the rectangle box the bilge pump resides in. So it is a relatively slow leak but persistent. And no it doesn't leak when the engines are running provided the boat is not moving through the water.

Its likely others have experienced a similar issue with this model and possible make of boat. We are sailing to Antigua then Grenada in the next week so I'd like to resolve this issue prior to departing.

Well that should be definately helpful to discount the engine. I can see your frustration though. As it's salt water it clearly has to be a hull leak of some sort, either fitting or worse. Not a nice delimma to have.

[PaulinOz]

"Its likely others have experienced a similar issue with this model"
Why do you think that?
There would probably be somewhere in the vacintiy of 100 Lagoon 39 in the world at present, all only a few years old.
This may well be a one of fault just localized to your boat.

You say 2 to 3 inches in the bilge pump box, is this before or after the bilge pump has operated.
I assume this is the automatic bilge pump sump area in the center of the bilge area.

What ever the case you need to isolate the area this to water is coming from Fwd or aft.

As previously suggested tape a number of dry tissues in the water path in the lowest part of the bilge fwd and aft of the pump, then you can narrow down what section of the boat the water intrusion is from.

Hope this is of some help.