Carry the spares that keep critical systems running
By Don Casey
Our multi-year cruise was still mostly in front of us when our Yanmar diesel engine uncharacteristically refused to answer my call for more revolutions. We reached our next port on reduced rpm, and the following morning the engine would start, but not keep running. When an otherwise mechanically sound diesel engine refuses to run, the problem is either fuel or air. The secondary fuel filter was clean and full of fuel, and the air filter was also clean. But breathing involves both inhaling and exhaling, so I reached for my metric sockets and removed the exhaust elbow. Sure enough, it was blocked rock solid by seven years of accumulated salt spray–cooled carbon debris.
Fortunately, I didn’t have to think about the mechanics of getting a replacement. I carried a spare exhaust elbow on the boat. In less than an hour, our potentially derailed cruise was back on track.
If you think I carry too many spare parts, think again. Our supply of red wine takes up more space on board. Having a spare for everything does provide some security, but this costs money and space, both of which are in short supply on our boat. The best strategy is to identify what spares you need to cope with systems failures that would truly leave you stranded. Cell phones and express shippers make it possible to handle lesser failures in a more relaxed way.
My experience has been that there’s not much need to carry spare deck gear. My theory is that rigging failures, including those involving running rigging, should be prevented rather than repaired. You do, however, need to carry at least two anchors; more is always better. If the windlass switch fails, you can bypass it. If the windlass fails, a sheet or halyard winch can stand in.
You can repair most sail damage, temporarily at least, with a roll of sail-repair tape. But if you’ll be away from home for more than a weekend, you should also carry some oil-protected sail needles, a cone of filament polyester thread, and a yard or two of sailcloth.
An engine problem can quickly turn cruising into camping, so I believe it’s essential to keep the engine running. Even so, the list of spares needed to resolve the most common engine failures is surprisingly short. Most diesel failures are caused by contaminated fuel, so you should have plenty of fuel filters—not just one, but several primary and secondary filters. A spare lift pump, if it is not too expensive, is a worthy item to have in inventory, but you may be able to circumvent a lift-pump failure with a few feet of extra fuel hose and a gravity feed from a fuel jug on deck. The spare hose can also be used to repair a fuel-hose failure.
Overheating is the second most common engine problem, and here the culprit usually is the raw-water pump. Carry at least two spare impellers and, for a cruise of more than a few weeks, a spare pump. Having an extra pump on board means you don’t have to rush to rebuild a failed pump should its bearings or seal fail.
A centrifugal coolant pump will give longer service, but one day the bearing and/or seal will fail and disable the engine. Since there is no viable work-around with this unit, you should include, if you have the space, a coolant pump in your spares locker. A rebuild is possible, but I don’t recommend it, particularly if the pump is aluminum.
Because broken belts and burst hoses are a fact of life, you should always have a full set of spare belts and a length of every size of hose used on your engine, along with half a dozen properly sized hose clamps. PVC unions and tees will further expand your plumbing-repair options. If your exhaust plumbing includes an injection elbow, it will eventually have to be replaced, and having one aboard will keep you from being caught out when the moment finally arrives.
Starter failure is another fairly common problem, but a spare starter is expensive, heavy, and has only short-term value. When a belt breaks you definitely need a new belt, but when the starter fails what you really need is a repair shop. Fortunately, starters can be found anywhere there are automobiles. Since most starter problems involve a faulty solenoid, a good compromise is to carry a spare solenoid. However, if being unable to start the engine for a couple of days will create many other problems, you should think hard about carrying a spare starter.
If your engine’s drive train has a sacrificial coupling between the engine and the propeller, be sure to carry a spare. A spare prop of some kind is also a good precaution. Also carry prop nuts and a shaft key in case the installed prop is lost rather than damaged.
Keeping the lights on is a high priority for me, which is why a backup alternator—either dry-wrapped in a locker or installed on the engine—is one important spare part I am happy to have on board. If your alternator is externally regulated, you will also need a spare regulator. Beyond that, a full selection of fuses, spare bulbs for critical lights, and a spool of wire should be adequate for most repairs.
Given the importance of GPS navigation, you must have a backup unit; an inexpensive handheld is perfectly adequate. Paper charts are good to have in case of a computer or plotter failure, and a lead line can take over if your depthsounder fails. A good hand-bearing compass can serve as a spare if the main compass is damaged; when mounted above the skipper’s bunk it also makes an excellent telltale compass.
If your water pump is electric, carrying a seal kit is a good idea, but this still leaves you vulnerable to a motor failure. Carry a replacement pump or install a backup manual pump. If you have only one water tank, you should consider installing a second one with separate plumbing, or you should keep a few extra gallons of water in jugs.
Although you won’t really be stranded if the head packs up, life aboard will be much more pleasant if you can repair it. Carry a rebuild kit.
Since they do a lot of important work, dinghies must be repaired quickly when they are damaged. Carry plenty of patch material for an inflatable, shear pins for the outboard, and, if you like to explore, you should also carry a spare propeller.
In all, my spares inventory comes to fewer than 30 items. I know that having them aboard greatly improves my chances of being able to keep going on my own. I may be moving slowly, but I won’t have to stop and wait for others to help me. It’s an efficient commitment of dollars and space that won’t displace my supply of Pinot Noir.
The tool inventory I carry for common breakdowns is modest. Here are the basics. Include any special tools your boat requires.
Socket set Fasteners on engines are often accessible only with sockets, not wrenches. If your diesel is European or Japanese, you need metric sockets. Include at least a short extension for your ratchet.
Six-point combination wrenches A set of 8 to 10 combination wrenches in English or metric sizes (or both), depending on your needs, will handle alternator mounts, threaded electrical terminals, and toilet disassembly, to name just a few uses.
Water-pump pliers Often called Channel-Locks, the best known brand, water-pump pliers are a versatile gripping tool and are especially helpful for removing flexible impellers.
Needle-nose pliers Essential for removing cotter pins and for electrical repairs.
Screwdrivers Carry Phillips screwdrivers in at least two tip sizes plus a “stubby” and four or five slot screwdrivers of different blade sizes and lengths.
Strap wrench A rubber-strap wrench can be used to unscrew fuel and oil filters (a supply of which you should always have aboard).
Allen wrench set Hex-key sets come conveniently mounted to a handle like a Swiss Army Knife. You will need either English or metric, or both, to remove or tighten setscrews.
Pipe wrenches If your stuffing box needs to be adjusted, you will need wrenches that fit the adjusting nut and the locknut.
Ball-peen hammer The best boat hammer is a ball-peen because it’s built for hitting steel. Never use a wrench as a hammer.
Crimping tool The proper way to make an electrical connection is with crimp terminals, and you need a crimping tool to install them. If you expect to do more than two connections, also buy a wire stripper.
Digital multimeter You cannot fully diagnose an electrical problem without a multimeter. Carry an inexpensive meter and learn how to use it.
Don Casey and his wife, Olga, are cruising the Caribbean aboard their Allied Sea Wind sloop while working on a new book about boat maintenance.