The only two “tools” that some boat owners carry are a subscription to a towing service and a mobile phone. My guess is that most readers of Passagemaker want to be more self-sufficient, in which case the size of the toolkit will depend substantially on the location and duration of the cruising itinerary, and the level of paranoia about potentially crippling breakdowns.

When I set off from New Orleans in 1987 with my wife, Terrie, intending to sail around the world, I had on board a vacuum pump, an oxyacetylene kit, cans of refrigerant, and coils of copper tubing in case the refrigeration system needed repairing in some remote anchorage. And then there was a complete replacement variable pitch propeller unit. And of course, lots of tools and a bench vise.

All of this on a relatively narrow-beam, 39-foot, double-ended sailboat. The boat was 2 inches down on its waterline. There was barely room for Terrie and our year-old daughter, let alone the baby on the way.

Now you know why we did not make it out of the Caribbean.

Over the years, it has become easier and easier to get replacement parts pretty much anywhere in the world. I have steadily reduced what I carry. The vacuum pump, oxyacetylene kit, cans of refrigerant and coils of copper tubing are long gone.

Then, a couple of summers ago, I fouled the anchor on a mooring chain in France and fried the windlass on Nada when trying to free the anchor. Terrie and I are no longer young or fit enough to retrieve our 66-pound Rocna anchor and all-chain rode by hand. We had to rig up a mechanism using a cockpit winch. This effort prompted me to carry out an assessment of equipment that might be difficult to replace at short notice, and for which a single point failure could shut down our cruising. For example, the windlass motor, engine starter motor and alternator. The spares inventory crept back up again.

Through all the changes in the spares inventory, my core toolkit has remained almost the same as it was 35 years ago, and in fact contains many of the same tools.

Choosing And Stowing Tools

The choice of tools is unique to each boater’s needs. It depends on your boat and equipment, how ambitious you are with respect to repairs and maintenance, your skill levels, the available stowage, and how much you want to spend.

Cheap tools are typically worse than a waste of money. If they don’t break, they damage components that are being worked on, and they skin your knuckles when they slip. Skip the prepackaged, multipurpose toolkits, as they generally have cheap tools and cheap cases. You are better off figuring out your tool needs and then buying what you require.

If you stow tools in wet bilges, they will be rusted and useless when you need them. You need a dry, accessible location, which means the tools are competing for prime real estate on the boat. Securing the right location may take some negotiation between you and your partner.

Other than a socket set, which will have its own case, a great way to stow the most-used hand tools (screwdrivers, pliers, wrenches and the like) is in a sturdy piece of fabric with multiple pockets that can be rolled and securely fastened with a carrying handle, to make it easy to move around the boat without dropping anything overboard. I also have a number of rugged plastic boxes that fit the chosen spaces on board. Some of these are on their fourth boat and still providing good service.

Ninety percent of the jobs on a boat can be done with a relatively small toolkit. It’s the other 10 percent that require a variety of specialized tools.

I have all of the tools below except for one, and they fit in two relatively small lockers. The tools represent a significant investment, but quality tools only need to be bought once. Some of mine are almost 50 years old and came with me from England in 1978—in a carry-on metal toolbox weighing close to 100 pounds that I had trouble lifting into the overhead bin—and most are 30 or more years old.

And remember: None of these tools and supplies will be of much use if you do not know how to use them. The time to practice is at the dock, not during a crisis at sea.

Screwdrivers With Flat And Phillips Heads

Have at least three sizes of each. You also want one of each with as short a handle as possible (stubbies) for tight spaces. And, get a set of miniature screwdrivers for some electrical work, notably tightening and loosening the screws in terminal strips and similar electrical connectors.

Wrenches And A Socket Set

Depending on the boat’s equipment, you may need these in metric and American sizes. The sizes should run from ¼-inch (6 mm) to at least ¾-inch (19 mm), and preferably larger. The socket set needs at least a ⅜-inch drive. For heavier work, go for a ½-inch drive with a ½-inch to ⅜-inch adapter for smaller sockets. The wrenches should be box-ends—open at one end and closed at the other. A considerable step up in functionality comes with a built-in ratchet at the box end.

Spark Plug Wrench

This is necessary if you have an outboard motor.

Adjustable Wrenches

They can be useful on occasion, but if used on tight nuts and bolts, they are just as likely to slip, damaging the nut or bolt. It is handy to have a small and medium size on board, but not as a substitute for a decent set of wrenches.

Allen Wrenches

These are also known as Allen keys or hex keys. They’re needed for the head bolts on our boats. An appropriate set is an essential component of the toolkit. You may need metric and imperial versions.

Vise Grips

These are a must. They come with straight and curved jaws. If choosing one or the other, I would choose curved. Have small and medium sizes.

Water Pump Pliers

These are also known as slip-wrench and channel-lock pliers. They can be useful so long as they are well made. A large set of vise grips can take their place.

Needle-Nosed Pliers

Get the ones with long, pointed jaws for fishing things out of difficult spaces and similar tasks.

Strap Wrench

You will need some type of strap or metal band wrench, maybe in more than one size, to change fuel and oil filters. It is better to have a metal band wrench that makes a close fit with a filter than to use an all-purpose strap wrench. The latter can be difficult to deploy in tight spaces.

Oil Change Pump

If you don’t have a permanently installed oil change pump, you will need a portable one.

Hose Clamp Wrench

I highly recommend getting one with a flexible stem. These can be bent through 180 degrees to do up and undo hose clamps that are otherwise inaccessible. You may need two sizes.

Utility Knife

Get one with a retractable blade. This is yet another item where quality, particularly with how easy it is to retract and change blades, varies markedly. Test it before you buy it.

Retractable Tape Measure

This will occasionally come in handy. Some are calibrated in inches, some in millimeters, and some in both (imperial on one edge and metric on the other). The readability of the markings varies widely, so pull out the tape a few inches and have a look at it before buying.

Handheld Flashlight

You want one that can be maneuvered into tight spaces. A headlamp is particularly useful, too. And numerous cheap, lightweight LED devices are ideal.

Ear Protectors

These will save your hearing from time spent around an operating engine. I am paying the price for being careless with my hearing.

Safety Glasses

These are especially important if you are working around flooded (wet-cell) batteries.

Surgical Gloves

I recommend these for oil and fuel filter changes, and any similarly messy jobs—especially repairs that involve working with polyester and epoxy resins and hardeners.

Ball Peen Hammer

It occasionally comes in handy for tapping out gaskets. There are occasions when a certain amount of blunt force is required to shock loose frozen components. In this case, an impact driver will complement the hammer.

Pipe Wrench

This is occasionally useful on plumbing fittings, or to turn propeller shafts, but will leave small scars on the shaft that can generate corrosion. If you plan to use a pipe wrench on a propeller shaft, first wrap the shaft tightly in a rag to minimize the scarring.

Telescoping Mirror and Magnet

If you have deep bilges, a telescoping mirror and magnet are handy for fishing out nuts and bolts that get dropped. However, the magnet won’t work on brass or most stainless steel.

And, of course, you need a set of drill bits. The combination will come in handy for numerous jobs. Combined with a set of screw extractors, the drill will let you extract broken-off bolts. A center punch (a relatively short, metal punch that comes to a fine, hardened-steel point) will be needed to create a small dimple in the center of the bolt that is to be extracted, before you drill the extraction hole. Without the dimple, it will be hard to center the drill bit accurately enough.

Extension Cord And Drop Light

Carry a couple of spare lightbulbs for the drop light.

Set Of Hole Saws

If you have the electric drill, I recommend adding a set of hole saws to the toolkit for occasions when you want to run large conductors, or hoses, through bulkheads and other structures.

Caulking Gun

You may want to seal holes, or you may require sealant for other fittings. I have a caulking gun on board and always carry a tube or two of a quality caulking compound such as 3M Marine Adhesive Sealant 5200. Note that most sealants have a shelf life, so if they’re not used from one year to the next, they will need to be replaced.

Aligning Punches

If you will be removing heavier components from an engine, a couple of aligning punches will come in handy. These are long, tapered steel punches. Let’s say we are replacing a heavy manifold that is held with bolts instead of sliding onto studs. If you lift the manifold into place and then slip an aligning punch through one of the bolt holes into the threaded bolt hole in the engine block, you can support the manifold on the aligning punch. Because the punch is tapered, if you move it around a little, it will shift the manifold in small increments in all directions until a bolt inserted through another hole fits into the engine block and can be tightened.

Torque Wrench

Many critical bolts on engines must be tightened to a specific torque setting. This requires a torque wrench. On some torque wrenches, you screw in the end of the handle until a pointer lines up with the desired torque. The nut or bolt is tightened until the handle makes a distinctive click. On others (generally cheaper ones), as the torque increases, a Torque Wrench (cont.) pointer flexes over a scale. The nut or bolt is tightened until the appropriate reading on the scale is reached.

MAPP-Gas Torch

MAPP stands for methylacetylene-propadiene propane. It burns hotter than propane.

Clamps

Go with a small collection, spring-loaded and one-handed.

Mask And Snorkel

These are mostly for those times when it is necessary to disentangle the propeller.

Digital Multimeter

As a core electrical tool, this is the most useful tool on board.

Wiring Tools

To do any wiring work, you need a decent pair of cable cutters, an insulation stripper and a ratcheting terminal crimper. Buy smart: Poorly made crimps are the bane of electrical circuits on boats, and are a leading cause of problems and failures.

Crimping Tools

There are large cranking conductors attached to our engines and cranking batteries, and perhaps even larger conductors with a high-output alternator. If you want the ability to remake these conductors and add terminals, you will need a crimping tool. For occasional use, there are compact and effective devices that you hit with a hammer to make the crimp. This, of course, requires the hammer.

Screw-Holding Screwdriver

We frequently want to undo somewhat inaccessible small screws that are holding a terminal to, for example, a circuit breaker or busbar. If the terminal is a ring type, as it should be, then the screw must come all the way out to take the terminal off or put it back on. It is all too easy to drop and loose the screw. A screw-holding screwdriver will minimize the chances of this happening. You need two: one for slotted screws, and one for Phillips-head screws.

Soldering Gun

For electronics work, you will want to augment the toolkit with a soldering gun, solder and flux.

Infrared Heat Gun

There are many troubleshooting exercises in which we want to check temperatures. You can buy a heat probe (a thermocouple) to plug into most multimeters. However, it’s typically cheaper to buy an infrared heat gun. This is a terrific tool for finding resistive connections in electric circuits, for checking the in and out temperatures on heat exchangers, and so on. Given that a heat gun can be purchased for around $20 these days, there is no reason not to have one on board.

Infrared Camera

This is an even more versatile tool than an infrared heat gun, but if the camera is bought as a stand-alone device, it is considerably more expensive. There are devices that plug into a smartphone, converting it into an infrared camera. (The camera function of a smartphone should be put to frequent use when disassembling anything, mechanical or electrical. The photos provide a reference for where everything goes during reassembly. In addition, I have a camera with a fold-out viewfinder. I can push the camera into otherwise inaccessible spaces and turn the viewfinder to whatever angle is necessary to see things. A small mirror and flashlight can often be used to do the same.)

Borescope Camera

This provides access to even more inaccessible spaces, such as the inside of fuel tanks. It has a tiny camera on the end of a long, flexible stem, with a ring of minute LEDs around the camera. As with infrared cameras, these can be bought as a (relatively expensive) device or as a (much cheaper) add-on to a smartphone. 

This article was originally published in the May/June 2022 issue.