General Info: Seawater in the bilge

[faa50]

We are new owners of a 2014 Lagoon 39. Love the boat but I'm having an issue with getting seawater in starboard hull bilge every time we sail or motor the boat?? The amount is 2-3 inches above the bilge pump and consistently occurs for the past six weeks. At anchor or mooring or in a slip, no water enters. This problem has never occurred in the port hull.

As a "newbie" boat owner, having difficulty diagnosing the problem. I don't believe a have a leak but instead that I probably am failing to shut a seawater intake for a shower, sink, seawater toilet or some other piece of equipment. We have heads in both hulls but again no water entry in port hull. Watermaker is on port side so not the cause. Saloon sink has a seawater pump. Being new I'm cautious to shut values unless I know what I'm doing and the consequences.

Can any of you with a similar experience share your wisdom - would be much appreciated.

[alctel]

I had/have that - checked the stuffing box on the prop and the rudder stuffing box? In my case it was the rudder one

[katsumi]

Good that you have established it is salt water, I always teach my crew this is the first step in finding water leaks.
Next step can you please list all the trough hull fittings in this hull? I would check around each of these with a good flash light and a dry rag.
Also check the speed sensor transducer.
I am assuming your vessel would be quite simular to ours, you will have 2 hoses with valves on them leading to the lowest point where the bilge pump pick ups are, one coming from forward compartment in the pointy end, and one coming from the aft engine room compartment. Check that the water is not coming from either point.
I have read about some people having the bilge line and the shower sump drain going into the same line, which it would have a check valve (one way valve) This would be something to check.
You will need to mop out the water and with a good light wait and watch as it sounds like a slow leak, watch for water steaming and follow where it is coming from. Look carefully at the bilge pump pick up well.
Hope this helps.

[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?

[TurninTurtle]

Check ALL hull penetrations and hoses/pipes that go to sea.

Motor/prop shaft will leak more when the prop is turning. Similar for the rudder.

When the boat heels or a wave comes along the side then the hull penetrations on that side can submerge.

And... waves that make it to deck level might find cracks to have water seep in. (least likely from your description... I think its going to be something below the gunwales)

A stuffing box may not leak at all when the shaft going through is stationary. I've seen that with the valve packing on a 800 lb pressure steam valve. No leak unless you are turning it but you better be wearing heavy gloves and watch where your hands are relative to that valve stem... because a tiny steam leak can cut your arm off.

[jeepbluetj]

Not if it was a leaky stuffing box. My rudder gland (on my monohull) leaks when powering. It's because of the prop "throwing" water up the rudder shaft. Doesn't leak a drop when sailing or when sitting still.

I don't know anything personally about a Lagoon 39, but based on the symptoms it's rudder or engine related. So could also be a leak in the cooling water circuit.

[barnakiel]

Taste it to know whether it is seawater or fresh water. Skip this test if you are on a river or lake.

They say toilet water has distinctive taste too. I can't tell as our bilges are bone dry.

Now that you know where it came from, go to that location and fix the problem.

If you have good access, you can dry the area very well then tape some tissue around. Water will wet the tissue and show you from which part of the boat it flows.

Have fun,
b.

[StuM]

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?

They are called "limber holes".
Try blocking them on a short trip and see if the bilge still fills. If it doesn't unblock them one by one and see which end the water comes from. That will narrow down where to look.

(If the bilge does fill with the holes blocked, pump it dry and then unblock the holes one by one - just in case there is more than one source)

[katsumi]

Originally Posted by faa50

We are new owners of a 2014 Lagoon 39. Love the boat but I'm having an issue with getting seawater in starboard hull bilge every time we sail or motor the boat?? The amount is 2-3 inches above the bilge pump and consistently occurs for the past six weeks. At anchor or mooring or in a slip, no water enters. This problem has never occurred in the port hull.

As a "newbie" boat owner, having difficulty diagnosing the problem. I don't believe a have a leak but instead that I probably am failing to shut a seawater intake for a shower, sink, seawater toilet or some other piece of equipment. We have heads in both hulls but again no water entry in port hull. Watermaker is on port side so not the cause. Saloon sink has a seawater pump. Being new I'm cautious to shut values unless I know what I'm doing and the consequences.

Can any of you with a similar experience share your wisdom - would be much appreciated.

I just read your post again and you mention you have water 2-3 inches above bilge pump?
Can you confirm if this is a submersible bilge pump?

[StuM]

Faa50, from your description it looks as though you have about 15 litres of water there. (14 x 18 x 4 = approx 1000 cubic inches or 16l)

How long does it take for that much to build up?

Have you monitored it while sailing to see if it a steady increase or whether is is building up in "spurts" ?

[boatman61]

Two questions..
1/ Are engine compartments in Cat's not supposed to be watertight.. up to a certain height..??
2/ Don't smaller Lagoon Cats have Saildrives..??

[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.

[reed1v]

Sounds like your hull is opening up while under way. Might have a longitudinal crack in the hull just at or a bit above the waterline. 4-5 inches in four hours sailing is a serious situation.

[Cadence]

Originally Posted by StuM

They are called "limber holes".
Try blocking them on a short trip and see if the bilge still fills. If it doesn't unblock them one by one and see which end the water comes from. That will narrow down where to look.

(If the bilge does fill with the holes blocked, pump it dry and then unblock the holes one by one - just in case there is more than one source)

We must have gone to the same "school". Water tights are actually not, do to the limber holes.
One should also have a plug available to plug them and make a water tight water tight. Just in the event of a catastrophic failure in a compartment. One post, if I understood it sounded as if they had hoses running from the limber holes, in fore and aft bulkheads to the sump.

[jimtaylorofkw]

We had a leak, very small, but coming from a small crack on the bottom underside of the exterior exhaust pipe.
Sara II
Jeselo, Italy