How To Check A Boat Service History


How To Check A Boat Service History

Checking a boat’s service history can be very simple if the current owner of the boat has documented it properly. Unfortunately, this isn’t always the case. Sometimes the history has been lost, and it can also be difficult to decipher the service receipts. You may also want to understand if each service has been carried out at the correct intervals. Throughout this article we are going to explain the best way to find out about a boat’s service history, and what how to determine what should be included.

How can I find out a boat’s service history?

The first and easiest option, is if the owner has documented it with receipts or a log book. This will tell you exactly what was done and when. Sometimes these documents or log books get lost, and aren’t available at the time of sale. So what else can you do? The second option is to contact the dealership that sells the boat or/engines. Popular makes and models (Volvo, Mercury, Yamaha, Suzuki, Caterpillar, MAN etc.) all have online portals where dealers log their engine services and recalls. Sometimes manufacturers offer extended warranties if the servicing has been completed by approved dealers within the recommend timeframes.

What should be included in my service history?

The easiest way to find this information is in the owner’s manual. An owner’s manual is provided with an engine when the boat is sold, or can usually be downloaded from the manufacturer’s website. The owner’s manual will outline what needs to be completed with periodic maintenance recommendations and intervals. 

On a small trailer boat, it can be as simple as checking the make and model of the engine fitted to the boat and referencing the owner’s manual. But don’t forget about the boat trailer! Trailer and braking systems need regular maintenance, and should be inspected at the same time as your engine. On a large motor yacht, you may have a number of engines, generators, gearboxes, water makers and other equipment onboard that will require servicing and have separate owner’s manuals you will need to investigate.  As a general rule of thumb, most recreational marine engines will recommend yearly service intervals or every 100 hours, whichever comes first. Don’t be fooled into thinking if you haven’t used the boat you don’t need to service it, because annual servicing is still recommended even if you haven’t clocked up the hours. Lastly, some larger diesels can include bi-annual or 200 hour intervals. The most accurate way to find out is by looking up the specific model of engine on the manufacturer’s website and referencing the owner’s manual. The more horsepower the engine is putting out relative to the displacement, the more regular and involved the service intervals will be.

What are some common items you will find in an annual periodic maintenance schedule?

Some of these will vary depending on the type of engine or gearbox, but here are some common things to find:


  • Replacement of engine oil and filters
  • Replacement of gearbox oil
  • Replacement of fuel filters
  • Replacement of impellor 
  • Replacement of anodes
  • Removal of sterndrive or gearbox, and inspection of universals or bellows
  • Grease components
  • Inspection of spark plugs
  • Inspection of belts

   2-10 Years

  • Cleaning of saltwater cooling systems, such as heat exchangers, after coolers, oil coolers and seawater strainers
  • Inspection of thermostats and coolant caps
  • Replacement of coolant
  • Replacement of water and oil seals in water pumps, gearboxes and engines
  • Replacement of timing belts
  • Checking valve tolerances
  • Replacement of perishables such as belts and hoses
  • Torquing of engine mounts, cylinder heads and exhausts
  • Bleeding and replacing hydraulic oils in steering and hydraulic systems
  • Servicing skin fittings and sea cocks  

This is not an exhaustive list, and it’s always best to reference your owner’s manual for specific information about what needs maintenance and when.

What else can I learn from the Service History?

A boat owner is most likely to do either regular preventative maintenance, or breakdown maintenance. When reviewing invoices from repairers, it’s good to read the entire invoice, as they often leave notes about any concerns or directions they may have received from the owner. But what is the difference between preventative/scheduled maintenance and breakdown maintenance?

Preventative or Scheduled Maintenance

Preventative or scheduled maintenance is the preferred type, which is when the owner has been following a service protocol as specified by the manufacturer in the periodic maintenance schedule of the owner’s manual. Following a good scheduled maintenance plan will also increase the value of your boat when it’s time to sell as it will instil confidence in the person purchasing.

Breakdown Maintenance

Breakdown maintenance is the least preferred type of maintenance. It’s when the boat has “broken down” and has been unable to operate without repairs. Breakdown maintenance is often carried out when the boat has been left unmaintained for long periods of time. For example, if you notice service receipts for items such as starter motors, batteries and alternators on low hour boats, it’s likely because they’ve got wet due to neglect and had to be replaced.

Overall, a well maintained boat has many merits including increased value, peace of mind and proving much less chance of causing you and your family issues while out boating.

About The Author

After a decade repairing engines as a Marine Mechanic, Aaron O’Donoghue’s passion for boating grew into a Marine Surveying business called BoatBuy. With a team of Marine Surveyors and Engineers, Aaron personally assesses over 200 used boats boats each year.