Seawater in the bilge

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   I have a strange problem. My boat, a Hanse 385, was sailed from Korfu to Croatia. I was not onboard. When the boat was back in Croatia I discovered seawater in the bilge, but only in the opening in front of the ladder, in front of bathroom and a bit under the kitchen. All other places were dry. After using the bilge pump the places dried and I removed an amount of dirty, brown salt. Now it stayed dry.
Has anybody an idea from where the water comes?
There were no waves coming into the cockpit.
Axel

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Axel Members Profile Send Private Message Find Members Posts Add to Buddy List Commander Joined: 08 May 2016 Location: Ugljan/Croatia Status: Offline Points: 91	Post Options Post Reply Quote Axel Report Post Thanks(0) Quote Reply Topic: Seawater in the bilge Posted: 06 January 2026 at 11:33
	I have a strange problem. My boat, a Hanse 385, was sailed from Korfu to Croatia. I was not onboard. When the boat was back in Croatia I discovered seawater in the bilge, but only in the opening in front of the ladder, in front of bathroom and a bit under the kitchen. All other places were dry. After using the bilge pump the places dried and I removed an amount of dirty, brown salt. Now it stayed dry. Has anybody an idea from where the water comes? There were no waves coming into the cockpit. Axel
	Hanse 385 #434 Nyanga 2

Arcadia Members Profile Send Private Message Find Members Posts Add to Buddy List Admiral Joined: 27 November 2017 Location: Sag Harbor, USA Status: Online Points: 1112	Post Options Post Reply Quote Arcadia Report Post Thanks(0) Quote Reply Posted: 07 January 2026 at 00:58
	Seems like it’s near the engine so I’d start there. Maybe a leak in the seawater cooling lines or a leak in the shaft seal. Saildrive? Or a vented loop needs service. You need to determine if it happens only when underway. It may be fine indefinitely when sitting idle.
	Leon / ARCADIA 2018 Hanse 588 Sag Harbor, NY

32mike Members Profile Send Private Message Find Members Posts Add to Buddy List Commadore Joined: 26 March 2020 Location: FLorida, US Status: Offline Points: 453	Post Options Post Reply Quote 32mike Report Post Thanks(0) Quote Reply Posted: 08 January 2026 at 00:25
	Could it be the hot water heater venting problem? Was it motored for a long time?
	Mike S/V Dulces Sueños 458 #087 Tampa, FL

Axel Members Profile Send Private Message Find Members Posts Add to Buddy List Commander Joined: 08 May 2016 Location: Ugljan/Croatia Status: Offline Points: 91	Post Options Post Reply Quote Axel Report Post Thanks(0) Quote Reply Posted: 08 January 2026 at 06:27
	This cannot be. It is saltwater.
	Hanse 385 #434 Nyanga 2

32mike Members Profile Send Private Message Find Members Posts Add to Buddy List Commadore Joined: 26 March 2020 Location: FLorida, US Status: Offline Points: 453	Post Options Post Reply Quote 32mike Report Post Thanks(0) Quote Reply Posted: 08 January 2026 at 14:44
	Just an observation for consideration. What starts out as fresh can seem like saltwater as it travels around and picks up whatever amount of salt is laying in the bilge. I’ve found it hard to tell sometimes. Did it look like this? This is what was coming out of my water heater while motoring. The color is from the rusted parts it was causing. Hope you find the cause. I hate to find water in the bilge that I can’t trace.
	Mike S/V Dulces Sueños 458 #087 Tampa, FL

Axel Members Profile Send Private Message Find Members Posts Add to Buddy List Commander Joined: 08 May 2016 Location: Ugljan/Croatia Status: Offline Points: 91	Post Options Post Reply Quote Axel Report Post Thanks(0) Quote Reply Posted: 08 January 2026 at 14:51
	The same is to me. The last 9 years my bilge was always completely dry. I cleaned it now and so far it remains dry. My suspicion is that the skipper who sailed my boat from Greece back to Croatia has somehow caused the water intake. My boat is in Croatia and there is no humidity in the winter. I know that boats in the baltic sea gather a lot of water inside. Where is your boat located? Greetings Axel
	Hanse 385 #434 Nyanga 2

32mike Members Profile Send Private Message Find Members Posts Add to Buddy List Commadore Joined: 26 March 2020 Location: FLorida, US Status: Offline Points: 453	Post Options Post Reply Quote 32mike Report Post Thanks(0) Quote Reply Posted: 08 January 2026 at 14:59
	My boat is in Florida in the US. There’s plenty of humidity here but I don’t suffer from condensation problems because I run the air conditioners in summer and keep it pretty well ventilated in the cooler months. All of that water you see in the picture was due to the water heater venting during motoring. Shower leaking out into the bilge is another source. There’s also the “hidden” bilge water that you don’t see. It’ll move around and show itself under heavier seas. Good luck with your search.
	Mike S/V Dulces Sueños 458 #087 Tampa, FL

Tranquillity Members Profile Send Private Message Find Members Posts Add to Buddy List Captain Joined: 01 December 2018 Location: Hamble, UK Status: Offline Points: 267	Post Options Post Reply Quote Tranquillity Report Post Thanks(0) Quote Reply Posted: 08 January 2026 at 21:42
	Axel, A few thoughts that may help, all these have led to salt water ingress from our experience. 1. Check Antisyphon valve is not leaking, very common problem just needs cleaning with fresh water to resolve. Normally would drip into sump below engine but on a very long passage could be a lot of water and leant over might wash into bilge. 2. Check all hoses clamps are tight on cooling and exhaust system especially the exhaust outlet through hull that have been known to drip and reported in one instance on this forum failed with boat sinking. 3. Was it a rough passage? We have had on a big sea long offshore passage with lots of water over the deck seawater enter via the swan neck that routes cables from bottom of mast through coachroof. Could see water pouring down the bulkhead! Just needs sealing so water tight. 4. Check under the floorboard between the back of keel and bilge pump, this is the area that water normally gathers on our boat and only seen by unscrewing and lifting the floor boards so might be worth checking. All above can be resolved and normally we have a very dry bilge. Good luck! Jon

Infinity Members Profile Send Private Message Find Members Posts Add to Buddy List Sub Lieutenant Joined: 04 February 2021 Location: Isle of Wight Status: Offline Points: 12	Post Options Post Reply Quote Infinity Report Post Thanks(0) Quote Reply Posted: 13 January 2026 at 12:09
	I struggled for ages to identify the source of seawater ingress in my Hanse 455. It was only a problem on starboard tack in waves. The liferaft box was not properly sealed at the bottom. The transom flexes a bit too much there and the Sikaflex had split. I think the water ran forward through a stringer to the bilge compartments midships, so it wasn't evident aft of the steps.
	H455 Infinity of Yar



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