It’s impossible to carry tools for every repair situation you might encounter in a boat, but it’s easy enough to assemble a reasonably small and versatile set of tools that can address a big percentage of common maintenance and repair problems on board, or at least keep you running and able to limp back to port. And the good news is that these basic tools should cost less than $200 or so.
For tool stowage, some people prefer plastic tackle-type boxes; others are lucky enough to have a dedicated tool drawer or locker. But for many small-boat owners the best choice is a soft-sided tool bag that won’t damage the deck or woodwork, and that has pockets that make it easy to see and grab tools.
Phillips Head Screwdrivers
Slotted Screwdrivers - The same goes for flat-bladed screwdrivers: Bigger onboard machinery calls for wider blades and longer shanks. However, a set of 1/4- and 5/16-inch wide, three- and six-inch long flat-head screwdrivers will generally keep you out of trouble.
These well known tools can handle a big variety of problems.
Though smaller ones are easier to fit in a tool bag, a 16oz Claw hammer will give you the most usefulness, whether it’s loosening rusted bolts or prying other hardware bits loose by force.
Along with a kit containing general terminal ends (spades, rings, butts, etc.) for average sizes of wiring, you’ll need a tool to cut and strip wire, and crimp on terminal ends. You can find one tool that does all three jobs. Such combination tools aren’t as good as separate, dedicated ones, but they can get the job done and they’re easier to stow. Don’t forget to toss a roll of electrical tape in your bag. As for those terminal ends, make sure you buy marine-grade terminal ends from the Chandlery, not cheaper alternatives from the auto-parts store. They are in no way the same.
Calipers/Fold Out Ruler/Tape Measure
While you generally will not need either of these to make a repair, they’re handy for making a shopping list of pieces and parts you need for a job, such as hose and hose clamps in the correct sizes.
Needle Nose Vise Grips/Vise Grips
There are few more useful tools on a boat than a set of regular and needle-nose Vise Grips. ‘Nuff said.
Adjustable "Crescent" Wrenches
We recommend adjustable wrenches versus a socket set because we’ve sacrificed more than our fair share of sockets to the bilge gods. There are certainly specific jobs where a socket will do better, but for everyday jobs, a set of six-, eight-, and 10-inch adjustable wrenches are good to have.
Universal Filter Wrench
Whether you’ve got an outboard or inboard engine, having the tool to make an oil or fuel filter change aboard is essential. Make sure you have spare fuel and oil filters aboard, too.
Spark Plug Socket
You keep spare plugs in your spares kit, right? Well, you’ll need to be able to swap them out, so make sure you have a proper socket (and ratchet) aboard to fit the spark plugs for your engine.
We like to keep a few sharp chisels aboard, along with a putty knife for prying and scraping. The chisels will get dull over time (and you need to be careful with them until they do) but are very useful in a number of situations.
Need we say more? We’re big fans of Gorilla brand duct tape, from the Gorilla Glue folks. That said, duct tape is for temporary repairs; the adhesive leaves behind a sticky, gooey mess if the tape is not removed soon enough. But you'll be completing the repair correctly once you return to shore, right? So that shouldn't be an issue.
Allen/Hex Key Wrench
Keep a full set of foldable Allen wrench/hex key sets in your onboard bag in metric and standard sizes. You’d be amazed at the mix of standard and metric hardware on a boat.
Another onboard tool that will save you lots of time. This tool is great not only for cutting hose, tape, and small wire, but for all sorts of other jobs. Make sure to keep spare sharp blades aboard—or in the handle—too.
Though cumbersome and difficult to stow, a hacksaw is great for cutting wire-reinforced hose, rigging wire in a pinch, metal tubing, threaded rod, and more.
Longtime friends of surgeons, these small but tough pliers are great for getting into small places. You’ll never regret buying a pair.
Pliers: Needle nose and Regular
Quite often taken as a given, you'd be amazed at how many times these are forgotten. Many times they are used for "other" purposes, only to have the salt water take its toll on them, rendering them useless.
Whether it's measuring hoses, cables, whatever the case may be. A tape measure can come in very handy out on the water.
Wrenches: Both Standard and Metric
No need to go overboard here. Just a decent selection of the most common sizes will go a long way to getting in those places where an adjustable wrench just won't fit.
They don't take up much room and can come in extremely handy.
Magnetic (extendable) Pickup
If you've ever dropped a tool (or part) in a bilge, there's no explanation needed.
Bronze Wire Brush
This will be needed in more applications than you can imagine. Whether removing corrosion from rusty bolt threads or cleaning a gasket surface, always nice to have.
2″ Wide Paint scraper
Again, one of those tools that more than make up for the space they require.
First thing that comes to mind is WD40. The Go-To of all spray lubes. If you have the room, some spray Lithium grease can also come in extremely handy.
Circuit Tester (Multi-Meter)/Test Light
As we all know, water and electricity don't play well together. Meaning the chances of experiencing electrical "issues" while on the water is extremely high. And both of these are worth their weight in gold when it comes to quickly diagnosing the source of an electrical problem.
Battery Jumper Pack
If you have the room, as well as the funds, a good (well charged) Battery Jumper Pack can really help in a pinch. Some folks like to carry battery jumper cables as well, in case you have a fellow boater willing to lend a hand while out on the water. Or even on the launch ramp, for that matter.
One more thing. Always keep your tools in optimum working condition. And one way to assure this is to give your tools a good spray down with WD-40 or any other water-displacing lubricant at least once a season (or after putting them to use) to keep corrosion at bay.
Once you’ve let the spray lube soak in for a while, give each tool a thorough wipe down with a rag and return it to the tool bag, and be sure to keep your tool bag (or whatever "container" you choose to use) handy, but as far away from the bilge as possible.