2000 370 AC, aft bilge alarm....help

[Kevin.F]

My aft bilge alarm goes off in rough seas. Usually when I take any sizable waves off the Port aft stern area. I have 3 thru hull connections there and I suspected that the hose on one of them was cracked. I had the inside wall taken down and the hoses appeared to be ok.
Water is somehow getting inside that area and naturally running down to the aft bilge area which sets off the alarm in the upper cockpit. Once we
hit the reset button on the monitoring system it shuts off....til the next wave.
If I travel on a calm day the alarm never goes off.
Once I'm anchored or at a dock the alarm does not go off.
If I squeeze behind the wall in the aft cabin and look down into the aft bilge area I usually see no more than a 1/2 " of water there.
Any thoughts?
Thank you for any comments.

 

[Boater420]

Welcome to CSR!

Maybe you have a bad float that's causing the issue? Have you been able to reach your hand down there to test the float by moving it manually? If I'm understanding you correctly a 1/2" of water shouldn't be triggering the float.

 

[rondds]

Do you have a bilge pump in the swim platform storage area? My friend with a 420AC does and water will get in there underway causing the float to trigger the pump.

 

[Kevin.F]

Welcome to CSR!

Maybe you have a bad float that's causing the issue? Have you been able to reach your hand down there to test the float by moving it manually? If I'm understanding you correctly a 1/2" of water shouldn't be triggering the float.

I believe the float is working properly. The 1/2" of water I see is when I'm back at the dock and I'm able to squeeze back there to look. I definitely think water is running into that aft bilge area when I'm underway in rough seas.

 

[Kevin.F]

Do you have a bilge pump in the swim platform storage area? My friend with a 420AC does and water will get in there underway causing the float to trigger the pump.

No bilge pump in that area. However, I've suspected that shore power compartment as the source of water entry. I'll need to look into that further.

 

[rondds]

If your dockside water hookup is in there and it drips, it could leak into that section. I know you said it happens when under way but sometimes standing water will slosh or move when you're on plane and trip the float switch. Have you checked to see if it's fresh or salt water? Gross, but a droplet on the tip of your tongue followed by profuse spitting will tell.

 

[Kevin.F]

Already did the taste trick.... its salt water. I can almost predict the wave that's going to set it off. Im pretty sure it's result of a larger wave hitting port side stern.
I've been thinking it's water being forced in through the thru hulls????

 

[Kevin.F]

Thanks all for the suggestions.

 

[sandydlc]

Is it possible that it's coming in through the aft engine vents? You definitely want to identify the source of that water coming into your engine room. You will start getting corrosion on both vital and non-vital systems. This is not a problem you want to ignore.

I wonder - would it be helpful to do a test while you're at a dock? Go into the engine room while someone else is spraying your aft port side with a hose? Fresh water won't damage anything but this test could potentially identify where your leak is.

Good luck.

 

[Capt. Rusty Higgins]

Kevin F....

If you will PM me a number and good time to call, I do believe I can provide some insight to your issue.

Rusty

 

[The Bill Collector]

Rub rail joint ?

 

[Glenn Goetzinger]

Had that problem, found that when the wave was hitting my port side sten, water splashing into the bilge intake air vent, runs down in bilge an was setting alarm off.