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On a boat everything is going to need maintenance. You can’t get away from it. Here are a few cruiser maintenance rules to help you understand it’s importance:

    1. You are working in one of the most corrosive environments on the planet.
    1. Things will wear out from use, and things will corrode from non-use. You can’t win.    
  1. Stainless steel will rust.

On our boat, I, Cruising Dad, am in charge of boat systems maintenance. I’m a former soldier, a mechanical engineer, and always, a gear head. Cruising Mom asked for my help explaining basic maintenance concepts and, ultimately, share my maintenance routine to help get you started.

There are two types of maintenance: scheduled and unscheduled.

You can think of maintenance as a constant, and scheduled and unscheduled as factors. By and large the more scheduled maintenance you do, the less unscheduled you need to perform.

Scheduled maintenance

Scheduled maintenance is self explanatory; it consists of those tasks that you have designated to repeat on a schedule. Scheduled maintenance is done on an interval, like weekly, monthly, quarterly, etc., or before an event, like start-up or use. Scheduled maintenance is preferred over unscheduled maintenance because you perform it at your leisure, generally at an comfortable anchorage, and with all the the parts that you need. 

Unscheduled maintenance

Unscheduled maintenance is essentially ‘emergency fixing things’. Unscheduled maintenance is done at the parts leisure, and you should know most of the parts on your boat have an evil sense of humor. Parts think it’s damn funny to see you skinning your knuckles while contorted into an impossible position while other parts are digging into your ribs, all while you are trying to get somewhere in 5 foot seas. 

Preventive Maintenance Checks and Services (PMCS)

No mater how much scheduled maintenance you do, you WILL have some unscheduled maintenance. The key is to minimize it as much as you can. Scheduled maintenance is also known as Preventive Maintenance Checks and Services (PMCS). You should have a maintenance logbook with a written PMCS schedule and log. The PMCS schedule and log are two different elements. The schedule tells you what maintenance is coming up, and the log is a record of the maintenance you’ve done. They are essential. 

In your logbook, write down the nomenclature (manufactur and model #) of all the maintenance equipment on your boat so it can be easily referenced. Your PMCS is dictated by the complexity of your boat and should also be noted in your logbook.

My PMCS Routine

Going into the details of maintenance on the engines, outboard, water maker, winches, generator, standing and running rigging, batteries, A/C, refrigeration, toilets, plumbing, electrical, etc. would be overwhelming, so I’ll simply share MY PMCS routine.

Event Driven PMCS (before start-up/use)
    • engines – oil, coolant, belts, hose clamps, fuel bowl, leaks, pre-filters
    • bilge pumps at engine check
    • toilets – leaks, fluid level
    • running rigging – frays
    • generator – oil, coolant, belts, hose clamps, leaks, pre-filters
    • water maker – oil, run water maker every 5 days
  • fridge/freezer – constant temp readings
Weekly PMCS
    • seacocks – open and close 3 times
    • pre-filters for shower sump – clean out
    • bilge pumps – tip the floats
    • manual bilge pumps – pump
    • dinghy engine – leaks and corrosion, zink, look for dinghy repairs
  • A/C – leaks, operational
Bi-Weekly PMCS
  • bottom – cleaning/inspection, zinks
Monthly PMCS
  • batteries (lead acid) – water
Bi-Monthly PMCS
  • water maker – pre-filters (20 and 5 micron)
Quad Monthly PMCS
  • water maker – carbon filter
Annual PMCS
    • engines – oil, coolant change, all fuel filters, impellers, belts
    • outboard – gear lube change
    • winches – re-grease
    • windless – gear oil change
    • sink – carbon filter
    • standing rigging – inspection
  • anchor chain – inspection
Unscheduled PMCS (i.e. Things I know will break, I just don’t know when.)
    • toilets – have complete sets of rebuild kits, and extra joker valves.
    • electrical – The vast majority of electrical issues are connections. Have sets of marine electrical heat shrink connections and wire. Soldering equipment a must. A good set of cutters, crimps, strippers, and butane heat gun is extremely useful.
    • lighting – Usually a connection problem, but if not, have bulb replacements.
  • major mechanical problems – have spares.

Boat Spares

You should determine your spares plan. Your spares plan will determine your spares package (what spares you have onboard). Your spares plan is dictated by your operational availability (how often you expect the equipment to be working when you want it to). If you are a weekend cruiser, when something doesn’t work, you can just go to the store and get parts, so you don’t need much of a spares package. When you’re a liveaboard cruiser, in-town transportation can be more of a challenge, so you need a more extensive spares package.  Ideally you want all of your equipment working every time you want to use it, but, unfortunately,  that is not typically a cruiser’s reality. Your operational availability is limited by your budget, your fix-it ability, and your ability to acquire spares.

Your fix-it ability

The availability to get something fixed depends on you. If you are able to fix nearly everything on your boat, then the availability to fix something is simply whether you have the parts and tools. This eliminates all but the most complex issues. If for some reason you would rather have someone else do the work, you’ll need money, and you may be limited to where the work can be done.


The spares package requires some decision making.

    1. Look at your PMCS routine. Stock all of the parts that you will need for a given amount of time.
    1. Think of your major equipment, and what is needed to make it work. This category includes spare pumps, lots of electrical fittings, a general assortment of hardware, sail repair sewing kit, and that kind of stuff. Add into your calculations parts you’ll need that may be hard to get in exotic locations, and get them when you can.
  1. You will need emergency spares. These are the items needed for temporary emergency repairs just to limp you along until a real repair can be done. DO NOT GET CAUGHT THINKING A TEMP REPAIR IS GOOD ENOUGH. Emergency spares also include duct tape, quick drying epoxy, lengths of wood, plugs, fiber glass repair, and so on. 

Engine advice

You don’t have to be a diesel mechanic to maintain your engines. Engine/transmission PMCS should be event driven. Within 24 hours before start-up, you should check the oil, coolant, belts, hose clamps, fuel filter bowls, and any leaks. Fluid levels and colors can tell you a lot about an engine. If you are losing a fluid, figure out why. Fluid quality is critical on an engine. 

Use Amsoil products. I first started using Amsoil products on race engines and saw great improvement over Mobile1. They are fully synthetic and designed for specific applications without compromise. As an example, we have a cat with two Yanmar 4 cylinder (4JH3E) engines. Our cat was a charter boat and had the refrigeration run off the port engine. The port engine had over 7600 hrs on it; the starboard was closer to 6100. The port engine ran cold, had a long start, and wouldn’t rev over 2800 rpm. The surveyor said it was shot. As an engineer, I knew better. Once we bought the boat, I changed the oil to Amsoil Marine HD 15w40, added their diesel treatment to the fuel, changed all the filters, and replaced the thermostat. The improvement was not instantaneous, but within 50 hrs, my starting cranks went down to less then 3 seconds, my max RPM recovered, and engine smoke all but disappeared. Now that we’ve gotten over 8000 hrs on the port engine, it is running like a champ. Amsoil also has a HD metal protectant; it is a spray on grease/wax. It sprays on as a liquid and hardens to a non sticky protective coating. I cover just about everything in it. If you are interested in these products, here is my Amsoil link. Feel free to send me an email too.

If you found this Cruising Dad’s article helpful, check out
Sailing Techniques On A Cruising Cat

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