Over the years multi-tools have become so sophisticated and sturdy that they often supplant (or augment) the individual tools boaters carry in their onboard toolbox. In many ways they have outgrown their ancestors, the Swiss Army knife and the Boy Scout knife.
If you have one, you ought to carry it. And it should be easy to deploy and use. In addition, it should include the components you think are most useful to you and your style of boating. Comfort is a relative term because the dual-purpose handles of multi-tool pliers were not designed with ergonomics in mind as they also store a raft of smaller tools. But the tools come in different sizes and shapes so you should pick them up and unfold them to check how well they fit your needs. This varies by model, but we find the Leatherman Wave a very comfortable tool.
For strength most multi-tools are made from hard AISI series 400 stainless steel, but that does not mean they are rustproof. Hard steel has a high iron and carbon content and thus offers rather low resistance to corrosion. Some brands offer titanium nitride coating, which gives the tool a shiny golden appearance. It offers better protection against corrosion but comes at a higher price. It is always good to rinse multi-tools with fresh water immediately after they were exposed to the ocean environment and spray with a light oil or corrosion preventer.
Because of the high iron content in their steel, multi-tools have the potential to upset a magnetic steering compass if kept in close proximity.
This decision depends largely on what type of boating you do, and what your job on board is. A multi-tool is a toolbox on your hip that contains up to a dozen or more miniature versions of tools you already have in full size, but that are tucked away in a drawer, box or bag. Pliers, scissors, wire cutters, standard and Philips screwdrivers, an end wrench, different knife blades are common on many full-sized multi-tools.
To handle heavier duties such as rotating, holding or compressing, we recommend multi-tools with locking, spring-loaded or slip-joint jaws, and an adjustable wrench. Some of the “tools” in a multi-tool such as bottle and can openers, tweezers, nail file, small screwdriver (for tightening the hinges of your shades) or mini scissors aren’t found in a regular toolbox, but can be of great value on any size boat.
The Leatherman Charge AL has aluminum alloy handles, a diamond-coated file, and bronze bushings. The 154CM premium stainless steel clip pointed knife holds its edge three times as long as typical stainless steel, and it includes needlenose and regular pliers, wire and hard-wire cutters, serrated and straight blades, scissors, drivers, saw, files, strippers, eight double-end bits.
Because of their varied shapes, sizes and features, multi-tools are best personally inspected before purchasing. Play with the locking mechanisms; see if you can easily deploy the tools that are most important to you. But even if you want to go all-out on the purchase of a multi-tool, it is still a good idea to keep a sharp boating knife in a location that is known and easily accessible to everyone.