Water leak 2004 hunter 36

Mar 27, 2016
90
Hunter 36 Hingham
I've noticed some water behind the area where my thru hulls are in the little round cutout hole at bottom of stairs . Dosen't look like its comming from stuffing box or hot water heater it seems like fresh water not salt but im not a 100% I dont like finding any water so I cleaned it out shut my water system down. Any ideas what it could be would be coming from ? Im adding a Picture to show the area . Thanks in advance for any help
 

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May 17, 2004
5,764
Beneteau Oceanis 37 Havre de Grace
You could try placing some paper towels in the area and checking them periodically. That might give you an idea of which direction the water is coming from.
 
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Jan 19, 2010
12,669
Hobie 16 & Rhodes 22 Skeeter Charleston
food color in a tank can also help narrow down suspects.
 

jssailem

SBO Weather and Forecasting Forum Jim & John
Oct 22, 2014
23,529
CAL 35 Cruiser #21 moored EVERETT WA
Identifying the water as fresh or saline will reduce the places you need to look.

Fresh water could be from your interior storage (hoses, pipes, valves). If it is a leak in your pressureized system, you will hear the pump kick on even if all the valves and faucets are closed. If you eliminate the internal sources, then look for fresh water, such as rainwater. The usual suspects include ports, hatches, and hardware fixtures on your boat deck.

Saline water has to be coming from the hull or water that is splashed onto the boat while sailing. Suspects include your propshaft, through-hulls, hoses/valves from through-hulls.

It is a process of elimination. Good luck
 
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Jun 17, 2022
301
Hunter 380 Comox BC
Lots to look at here.... from the wood above being delaminated, you have or have had a leak above that area. One hose appears to be not marine rated. The valves are likely household valves as the handles are not stainless. White pvc hose is usually not rated for freshwater (drinking water), it should be clear (fiber reinforced) or blue. Clear unreinforced hose is only for drain lines (no pressure or suction). Finding the source of a leak remotely would be like asking us to bring back moon rocks without going to the moon. Paper is a good trick. Start high, then gradually place it lower. Doesit leak under way? When engine running? When filling tanks? When it rains? Water can travel quite a bit before making an appearance. What's the condition of the thru hull backing plates? Is the strainer lid too tight or have a damaged seal? Is the strainer case cracked due to the weight of the unsecured brass fittings ? The case of the pump where the quick connect fittings plug in can stretch and leak over time if they have any lateral stress. Some of these issues should have been picked up on your last survey...

The leak could be 20 feet away..... play detective, be methodical, and consider cleaning up the plumbing before a valve or hose fails.....

You'll have to taste test to narrow it down....
 
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Sergei

.
Sep 1, 2025
1
Carver Trojan express 400 Pittwater
Hi everyone, mine is a motor yacht Trojan 400 express, and I found at least one leak through a blocked drain in the area which couldn't be easily seen. Mine has two large air intake and engine room vent grills, recessed in the hull. At the very end of each it has a drain hole, hardly seen or accessed from the outside, with a drain hose fitted on the inside in the engine room. One of them was blocked causing leaks through less than perfect seals (which can't be accessed anyway without removing/breaking the whole plastic grills). Cleared the debris and it's all good now. Hope this helps
 
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