Friends of friends are on their way home on a new-to-them Downeast cruiser. The boat had been sitting on land for several years, and only has a hundred or so engine hours on it. She passed her survey, so they put her in the water to start their journey north from Florida.

Their troubles started when they hit some rough water on one of the open sounds on the ICW. Wind and waves shook the boat for the first time in years, and the single diesel engine shut down. They arranged a tow to a marina from Sea Tow or TowBoatUS, the towing services one finds all along the route.

It turned out to be a clogged fuel filter, and once the filter element was changed, they headed off again. But they were soon back to square one with a dead engine and another clogged filter.

My friend asked them if the boat had twin switchable fuel filters mounted with a vacuum gauge in an accessible location in the engine room. This should be standard practice on all cruising powerboats, especially trawler yachts and other cruising powerboats planning to go out for more than a simple day trip. The boat did not.

(Seen below: Example of switchable fuel filters with vacuum gauge.)

switchable fuel filter with vacuum gauge

They also subsequently learned their fuel tank pickup tube had a small screen fitting at the bottom of the tube. Someone must have thought that was a good idea, however wrong that proved to be…

Obviously, with the boat sitting idle for a long time, it’s likely water got into the fuel tank, perhaps as condensation through a vent during the daily cycle of heating up during the day and then fuel and tank cooling down at night. (Which is a good reason to keep fuel tanks either full or empty when the boat is going to be left for long periods.)

Water can also enter from a leaking, poorly sealed diesel fuel fill, or even come aboard as contaminated fuel from a fuel dock. Whatever reason water gets into the tank, it creates a diesel/water interface layer that is a perfect environment for bacteria to thrive, living in the water and consuming diesel. And discharging a nasty biomass slime that sits at the bottom of the tank, along with dead bacteria.

On top of that, many older trawlers were built with mild steel fuel tanks. Any amount of water in a steel tank will eventually corrode the interior walls and rust particles fall off to join the rest of the junk in the tank.

The above represent a recipe for problems when rough seas stir this mess into suspension.

It would have been ideal (had they known) for the couple to schedule a tank polishing before they left for a long trip north on their new boat. I’ve had great success with these mobile services, and their portable but powerful equipment remove biomass, asphaltenes, and water from a boat’s fuel tanks.

An even better way to ensure clean tanks and fuel, however, is to open the inspection port on the top of the fuel tank and physically inspect and clean whatever is in the bottom of the tank. I am also a huge advocate of onboard fuel polishing systems that not only filter fuel but also clean the tanks using a high-pressure flow rate. If one starts with a clean tank and religiously uses a fuel polishing system, the chance of fuel related engine problems approaches zero.

(Seen below: A fuel polishing system found on a Selene Yacht.)

fuel polishing system 

I am certainly not one to point any fingers about getting in trouble on a new boat. I had almost the exact same thing happen to me when we brought our new-to-us PDQ 41 power catamaran from South Florida to Annapolis. Boat looked great, survey was fine, and all was well…or so I thought. We left Stuart, Florida for the trip home.

Things were great in Florida as we headed north. Fine weather, comfortable flybridge, and the joys of running in sunny weather. The concept of the power catamaran really proved itself, and I was loving life. With engines located so far apart, I learned to walk the cat sideways, a champion of close quarter maneuvering.

However, just north of the St. Augustine Inlet, the port engine alarm went off. Having no idea what was going on, I shut it down and we continued with the starboard engine as I went down to see what was going on. There was water in the fuel filter bowl. I drained the water and restarted the engine. We continued, but now there was some anxiety in the back of my head wondering why we had water in the port fuel tank.

The port engine alarm came on regularly, and I got quite skilled in the process of draining water from the filter bowl. It was still a memorable trip, but I could not really relax with this water-in-tank issue following us all the way north.

When we got home, my local engine guys came out with their portable gear and cleaned the fuel. Over the course of 36 hours, their equipment removed several gallons of water from the port fuel tank. There were no leaks anywhere and none of us could find signs of where the water came from.

We never did solve this puzzle, and thankfully, it never happened again. But I went ahead and reinforced the fuel filtering systems in the engine rooms, which gave me confidence that I eliminated this as an issue.

Happy cruising is not just about having clean fuel filters, however, and there are other things one should stay on top of in the engine room. Hopefully there is sufficient room to move around and get to all the important systems. As I have said many times, access to your systems is perhaps the most important element in finding the right boat for you. Access is that important.

Such learning experiences also happen to owners of brand-new boats. After commissioning and sea trials, owners expect to jump aboard and bring their new trawler home. No one expects anything to go wrong. But that is not how it goes most of the time.

Often it is just little things, but there are enough of them to put together a punch list of things that need attention. Someone stores pots and pans in the obvious galley locker near the stove, unaware that an apprentice technician installed the autopilot compass sensor on other side of the cabinet side and the autopilot won’t work properly with so much metal so close. Door latches need adjustment, a stove doesn’t work, defective steering parts, leaks in the overhead, thrusters that don’t stay on, a dinghy that won’t hold air. I’ve seen all of that and more on a new boat.

Which is why it is so valuable to go use the new boat, but stay close by where you picked it up, whether at the builder’s yard, or your dealer. Getting the kinks out of a new boat takes time by using and exercising all the ship’s systems and controls. Sloppy steering may simply require bleeding the hydraulic fluid in the system (a good skill to learn), or electronics may need to be adjusted.

And the fuel delivery system, with so many hoses and fittings, especially on a large trawler with multiple tanks, may have construction debris that needs to be cleaned out. Some of these systems are also intimidating to new owners, so it helps to stay close where answers are never far away. And new owners need to make lists, lots of lists. 

trawler yacht fuel delivery system

Which is why I would love to buy a boat, such as a new Northern Marine trawler, and cruise the San Juan Islands and British Columbia as a summer shakedown cruise. It is the finest cruising anywhere yet still close to Anacortes to get things sorted out.

(Seen below: The engine room on hull#006 of the Northern Marine 57 has excellent access to the fuel systems.)

engine room on trawler boat

We came up with a couple of checklists over the years. Some were intended to be used by my editors when they did boat tours, so we were consistent. Others were a result of being on the board of ABYC to refine the guidelines for best practices in trawler construction. And even more came together after hearing stories like the one above about crud in fuel tanks, and simply from experience. While I am not a trained technician, you just learn things…

These bullet items are not collectively a complete list, and do not include things like checking fuses and exercising electrical switches. But they do represent potential problem areas that should be monitored, perhaps as part of your morning ritual engine room check before heading out. Or they can be reviewed every so often when you grab a beer, turn on the tunes, and sit down with your tool bag and rags to take it all in.

Hope this helps and perhaps the start of your own engine room checklist.


Engine Room Checklist

• Inspect engine and look for drips, leaks, belt dust, or fuel (or oil) streaks on engine block
• Engine mounts clean, tight, no rust
• Check raw water strainer and seacock
• Raw water pump - is it leaking through the weep hole? (Indicates an internal seal has failed)
• Inspect bilge pump
• Check oil filter (write service date on all replaceable filter elements)
• Check fuel filters (write dates of last change on tape on all filter housings)
• Sacrificial anode in heat exchanger (change when 50 percent)
• Examine muffler for cracks, leaks, corrosion (and examine any brackets in the exhaust system, particularly look for hairline cracks in welds)
• Check oil level
• Hose clamps (double below waterline)
• Transmission: check gear cooler, oil level
• Exhaust hose (check for leaks)
• Coolant cap (check for leaks)
• Inspect exhaust elbow (check for leaks)
• Make sure control cables are not kinked, and end fittings are securely fastened
• Genset:
   o Write change date on all replaceable filters
   o Inspect all connections and circuit breakers
   o Check belts for proper tension
   o Look at hoses, wires, clamps for cracks, brittle plastic parts and connectors
   o Check oil and coolant levels
• Check battery levels and terminals
• Inspect alternator for proper belt tension, alignment and excessive dust build up
• Inspect battery cable connections to and from alternator
• Check stuffing box and shaft seal
• Starter wires are tight
• If everything looks okay, start engine, and watch everything for a few minutes just to make sure.

There is tremendous satisfaction in catching some little thing in the engine room before it develops into a problem and threatens to ruin a day on the water.


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