A Bit About Bilges

Posted by on Jul 24, 2014

The leading cause of boat sinkings, mechanical failures, and fire can all be found in the bilge. That’s a bold statement, isn’t it? One has to be careful when you they are in the cause-effect business of marine damage surveys. Like degrees of separation, one could also make the case that not looking in your bilge may lead to your husband of wife divorcing you. I could make that case easily in four degrees, but it would not really stand up to an engineering challenge. It is not so hard to tie the perils of boating to neglecting your bilge.

Attend a pre-purchase marine survey and you will see a marine surveyor spends at least 25% of the time of the inspection in the bilge. The systems noted on the report, and even stuff that isn’t, were checked from the bilge and makes up the majority of the report. Yet, it is one the most neglected, overlooked, and unfamiliar areas to the boat owner and buyer.

Before anyone gets the impression that the intent here is to scold, know that I cannot cast stones. I was blissfully ignorant of the contents and working of my bilges before I decided to take on my first true restoration project, several years before I became a surveyor. Now, almost a decade later, and having seen hundreds of bilges, I am hoping to shorten the learning curve with a few tips, or at least encourage you to do one thing before you leave the dock, every time. Lift the bilge covers and look around.

A little anecdote…I was performing a re-insurance condition and value survey with the client on board, in the slip. The boat was also for sale. I had the bilge cover up and was working below when the bilge cover slammed on me without warning. I called out to the owner to make sure everything was alright above decks. He responded, “Yes, just hang on a second.” I could hear a conversation taking place, but couldn’t make out what was being said. I went on with my work until the bilge hatch was re-opened a few minutes later.

I asked the owner what happened. He said, one of the guys on his dock was walking past and he didn’t want him to think something was wrong with the boat. Evidently, having the hatch up is the universal symbol for mechanical failure on pier three at the local marina. I’ll skip past the safety issues and jerk client surcharges that could apply to this situation. I recognized that this is one of the answers to the question, why don’t people check their bilges regularly.

While vanity and salesmanship might represent a portion of the population, most people are simply overwhelmed. The bilge can look like a plate of spaghetti with two big, noisy steel meatballs. Tracing each noodle could make anyone feel lost. But the more you look, the less complicated it will seem and the more likely you are to see a problem before it becomes  a major expense. The settees in the cockpit and beverage cooler may be your favorite parts of the boat, but let’s look at what you are missing…below decks.

Water in your bilge? It is generally assumed you will have water in the bilge. A most competent local surveyor represents that you should not have water in your bilge. He makes a good case. Diligence could identify and prevent most sources of water in your bilge. Wet cores, stringers, bulkheads, as well as some rot problems can be attributed to water left in the bilge. But, if you choose to accept that there is going to be water in your bilge, checking the bilge before you leave can alert you to excessive water.

Are your bilge pumps working? Test them. They are not a means to keep you afloat while underway, but they will buy you time. Bilge pump failures are often the cause sinking at the slip.

Ok, start cursing me now. Keep your bilges clean. I have bruises and scars today which can be attributed to doing this job. Eventually I learned to recruit a high school or college kid, small in size, and wanting some cash. Give them a  safe working environment and the proper supplies and protection and turn them loose. They can get in places that I will never see again without a mirror or camera. What’s the point? Fuel, oil, hydraulic fluid, and coolant leaks all become very obvious in a clean bilge. Identify the problem before you go low on oil, overheat an engine, or loose steerage or trim, or worse, fire or explosion.

Focus on fuel. Those who have gasoline engines are hopefully running their blowers, but the diesel community is far more complacent. What they fail to recognize is the flashpoint for MDO marine fuel and similar grades is 60 degrees Celsius. To save you the trouble of converting, that is 140 degrees Fahrenheit. Some engine rooms are that hot from the summer heat, before you even start the engine. Many marine fires are attributed to marine fuel line failures resulting is diesel fuel on hot surfaces of engines. The nasty thing about diesel is it burns nice and hot. Gasoline tends to burst and burn out quickly (explode would be a better description). Diesel likes to keep burning. There is no better or worse here. They are both bad situations and you never want to be on or near a boat fire. Did you know that fuel line manufacturers are recommending replacement every 5 years? How many years since you replaced your fuel lines.

Look, listen, and smell. Get to know what things are supposed to look like so you know when they are not as they should be. Wiring which is discolored, loose, has exposed copper, or chafed should be inspected and repaired. Most marine fires start with electrical problems.

Check all hoses, but in particular, ones which supply raw water from the sea. These should all have functional seacocks. Work them so they don’t seize. If they cannot be closed, what if the hose fails? Look at the hoses for cracks, soft spots, and proper clamping. Any below waterline hoses should be double clamped. Are the clamps secure? A partial sinking case I worked resulted from a single clamp which failed due to a poor spring commissioning job. The owner was aboard when he noticed his comforter was exceptionally heavy when he tried to roll over at night. He awoke to find water up to his mattress. Yikes!

Look before and after the engines (and generator if applicable) are running. learn what your engines should sound like so you know when they don’t sound right. Most of us have experienced some engine trouble at some point and you can hear and feel it at the helm. You might find it before you leave the dock with a quick listen and look at the engines while you are giving them a few minutes to warm up.

Exhaust leaks can be tough to spot, but can be deadly, particularly on gasoline boats. CO is undetectable without a sensor / monitoring systems. I see these disabled or removed quite often. Ironic that it is because they are going off due to high CO levels in the cabin. Yes, they get old and will alert to low, relatively harmless levels when they are at the end of their service life. But most times they are alerting you to a CO leak into the cabin. If CO was purple and we could see it, it would be taken seriously and there would be very few casualties. As it is, we assume if we can’t see it, the alarm must not be working. Unfortunately, too many cases of CO sickness or death occurred because the threat was ignored and they were overtaken before they knew what was happening. Yes, it can happen to you.

I could discuss dozens of systems and checks that you could make, but even stepping up your diligence a little will go a long way to make boating safer and assure the best condition of your boat. The bilge cover being up should be the universal symbol of a diligent boat owner, not a problem. Instead, stand up and tell your dock mate proudly, I was just performing a quick maintenance check. I’ll bet they ask you what checks you perform and you will get a compliment and maybe an invite to check their boat for them. If nothing else, an excuse to sit in the cockpit with your cold beverage of choice and talk boats.

I hope this has helped.