Leaking boat: how one sailor traced the source

Boats have many problems and my Moody 376 Linga Linga was not going to miss out.

Many of these occur in the bilges, which are out of sight but should never be out of mind!

It was early in 2020 that I had my first indication I had such a bilge problem, when my lower level bilge alarm went off in the middle of the day, though fortunately while the boat was safely alongside its berth in Malta.

Bilge alarms normally go off in the middle of the night or when sailing (if you have an emergency) so I had much to be thankful for.

My first action was to switch off the alarm and then inspect the main bilge, where I discovered the appearance of water.

This immediately set off the brain’s panic alarm, for I’m allergic to finding water inside my boat.

The immediate problem was initially solved by the removal of about two litres of water.

Normally when you have a problem leak to solve on a boat it’s raining the proverbial cats and dogs.

However, in my case Murphy’s Law was activated and I had to wait a few weeks before we enjoyed a torrential downpour to enable me to carry out further investigations.

Analyse the evidence

I then ‘scientifically’ ascertained whether it was freshwater or seawater by tasting it, something not normally recommended.

This confirmed that the problem was freshwater – not as serious as the salty kind, but still a problem.

So, the source had to be found and then eliminated. Sounds easy? Wrong!

Finding the source of a water leak on a boat is like finding the source of the river Amazon, something that I believe is still under dispute.

I decided to follow the approach of that great detective, Sherlock Holmes, and be methodical.

The first step was to remove all traces of water from the bilge. Then I worked carefully back from the bow, searching for pooling, and found seawater in the forward bilge.

This had accumulated in 2020 when the head’s pump had refused to flush seawater into the toilet bowl.

The problem had been traced to the corrugated PVC multiflex hose, which had been leaking from the seacock.

This was solved by cutting away the hardened area of the hose and refitting the hose clips, tightening them to make a waterproof seal around the seacock.

After this discovery, I then proceeded to check and remove all traces of water from under all the floor areas back to the main bilge.

I felt confident at the time that I’d solved the problem. I was wrong.

If at first you don’t succeed

The water appeared once again so I mopped it out then patiently waited until we had another monsoon before having another look in the bilge – which was bone dry.

To borrow the catchphrase of a well known TV character: ‘I don’t believe it!’ Back to engaging the brain.

So, the next potential cause of the water getting into the bilge must be via the deck fittings when I washed the boat.

To check, I dried out the bilge but it was another ‘I don’t believe it!’ moment.

Despite no washing, bilge water had reappeared. The engaged brain was getting worn out with all these exertions.

The other potential cause of water in the bilge was from the fresh water tanks.

So all the hoses and connections were checked and the tanks filled to overflowing.

After the fresh water system had been thoroughly used for a few days the bilge was checked again. ‘I don’t believe it!’

The bilge was bone dry. Closer investigation showed the water seemed to be coming down the port side of the bilge’s moulded GRP wall via a small hole in the moulding.

Using a syringe, I then attempted to remove all the water from the recess and then laid paper towels around the area to confirm that I’d succeeded in fixing my leak.

Had I finally found the Holy Grail?

The search continues

A few weeks later I checked the bilge again, but discovered the paper towels had become saturated with water, confirming another failure in detection.

As the water in the bilge never exceeded two litres and could be removed with a sponge, I learned to live with this relatively minor inconvenience.

The months passed and I got into the routine of periodically checking the main bilge.

However, water would occasionally appear there as if by magic. This needed sponging out, which was annoying but not life-threatening and not one of the worst problems of life on a boat.

As I grew older (but no wiser) the mystery continued to confound me.

As Sherlock was not available to solve the mystery, I hoped that my two bilge alarms would give sufficient warning should the problem become more serious.

Soon we were into the summer heatwaves of 2021 with the temperature in Malta starting to rise above 40°C. This created a serious emergency, namely the problem of how to keep the beer cold.

In these temperatures my old fridge – like its owner – was struggling to cope.

Continues below…

Fortunately I was able to keep the fridge at an average internal temperature of 10°C by running it off the 220V mains electricity supply.

The holding plate had built up a large amount of ice around it, thus keeping the beer very cold.

This is the purpose of a fridge, of course, and enabled civilised life to be sustained, but it also revealed a clue as to why I was getting water in my bilge.

As the large build-up of ice was also affecting the fridge’s efficiency, once again Sherlock was called in to solve the case.

Investigation revealed that the holding plate had iced up to an unacceptable level.

Unfortunately after defrosting the fridge I encountered another problem, the fridge defrosting pump failed to pump out the defrosted water.

Solving this problem was not an enviable task. I’d previously replaced the defunct oven with a microwave, but to find out why the pump was failing I had to work in the confined space underneath it – a job for a contortionist.

The cabin temperature was 35°C, but the pump had to be checked, which meant disconnecting it at the sink. It was then immersed in water and operated successfully, confirming it was serviceable.

The pump was reconnected and the search continued. The defrosting hose was then traced to the culprit – a brass hose reducer connector.

Progress at last. However, further work was still required, which involved disconnecting the 20mm braided reinforced hose from the offending connector.

The end of this hose was then inserted into some water and the pump successfully pumped it into the sink.

Further investigation revealed that the hose clips around the corrugated PVC Multiflex 25mm hose were found to be tight.

However, it appeared that water had leaked from the end of the hose, which had hardened with age.

Fixing the leak

Solving the problem was relatively easy!

The task required continuing working in a confined space in a cabin temperature still at 35°C and suffering loss of skin from my knuckles in order to fit a one way hose connector non-return valve (NRV) – which should have been fitted originally – and then to tighten the hose clips.

The conclusion, after suffering considerable frustration and sweating about a kilo loss in weight, is that perseverance pays off and nothing beats the satisfaction of a job well done.

Lessons learned

Part of the problem had been caused by the plastic hose hardening at the terminus and causing a leak.

I’m in the process of switching the bilge hoses from corrugated (or ribbed) hose to reinforced hose.

1. On boats as in life, we don’t have problems, only challenges. If you discover water accumulating in your bilge, it must be coming from somewhere and could be much more inconvenient than just getting your feet wet. The cause could be serious. Therefore, the source should be ascertained as promptly as possible. In my case it was fresh water and not sea water, so less of an issue. Therefore, as I was human and lazy (a common trait among some of us retired men) I decided to live with the irritation. This was preferable to expending my limited energy on tracking down and immediately fixing the leak.
2. I was fortunate in that I have two bilge alarms fitted set at different levels – yes, I’m a belt and braces man. One runs off the 12V ship’s supply and is set at the highest water level setting I will allow. The second alarm is set at a lower level, which is a backup and operates independently from a 9V battery. The alarm goes off when I have accumulated about two litres of water in the bilge, and it was this alarm that first identified the problem. I’ve also replaced the PVC sanitised outlet hose on the heads with a reinforced PVC hose as these types are more pliable. As such, a better seal is achieved on the outlet seacock and the TruDesign one-way hose connector non-return valve reduces the water level in the toilet bowl.
3. If my fridge had not had a drain to leak defrosted water into the bilge I’d have been spared all my suffering and stress. This drain also leaked cold air causing a loss in efficiency, a problem I’ve attempted to overcome by fitting a removable drain plug.
4. The fridge defrosting hose connector should have had an non-return valve fitted which would enable the defrosting pump to function more efficiently. I’d also ensure I do not have corrugated PVC multiflex hoses as these harden and are more prone to leaking, as I discovered.
5. The moral of this story is that I should have engaged brain and remembered my previous problem with the leak from the heads seacock inlet, which was weeping sea water from the corrugated PVC hose. The hose had hardened and the problem was only solved when it was cut back to a more pliable softer area to enable the hose clips to be tightened sufficiently to make a leakproof seal. We should always keep our boats ‘shipshape and Bristol fashion’, which means in good order and efficiently arranged. In my defence I plead old age.

Let’s talk bilge

Tips from PBO’s Jake Kavanagh

“For me, the bilge for me is an area which all good sailors should treat in the way that ‘Cleanliness is next to Godliness,’” says Alan England.

“The bilge should always be kept clean and dry, for many boat problems originate there or give clues to problems elsewhere, as I was to discover.”

A tour of any modern boatbuilder shows that they wholeheartedly agree.

Here are some examples of good practice to avoid bilge-area problems, partly by making solid and dependable connections, but also by the fast identification of any pipes or outlets, especially important if there is a sudden leak at night or in a seaway.

• One good way to reduce the risk of leaks is to minimise the number of holes below the waterline. Known as a ‘manifold’, this multiple fitting uses just one through-hull instead of three. Note the double-and-opposed clipping, the earth wire, the flow-coated bilge area and also the clear labelling. This example was in a Cheoy Lee motoryacht built in Hong Kong.
• The builders of blue water yachts want plumbing systems to be resistant to vibration, temperature expansion and inertia. Clipped pipes should stay that way. Manufacturers often have displays of good practice in their yard for apprentices and customers to study. You can also get foam grip that allows pipes to expand within the bracket without damage.
• UK-based Discovery Yachts has a similar concept, with this board available for inspection on an organised yard tour. Colour coding, the correct type of hose and clear labelling are all employed.
• If you’re using the bilge area for stowage, another good tip is to add plastic ends to the exposed tails of the hose clips to stop them snagging fingers or popping fenders. Usually available in red or blue plastic, they slip on easily. Try and predict problems, too. For example, this cockpit drain runs near the exhaust so a partition will be added to stop an overheat melting the plastic pipe.

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