When it comes to troubleshooting and DIY projects, I think of blood.

I know, I know—you’re thinking that I have a very strange mind. But troubleshooting and do-it-yourself go together with blood like, well, juggling and chainsaws.

Blood, of course, is something many of us get used to from a young age. Skinned knees and elbows are a part of childhood, and Band-Aids are as familiar as a school notebook. Even more, when tinkering with boats, cars and tools, the color red is always in vogue (and not just for topsides and Ferraris).

And blood can show up at any time. My wife is a gourmet chef who works with fresh ingredients, which explains why she didn’t understand about can openers. Recently, she held up a thumb sliced by a razor-sharp can. There was so much blood, it could have been one of those fake rubber fingers you filled with ketchup as a kid and then pretended to cut with a knife. But no, this was the real thing.

I examined the cut with great calm and determined that it wasn’t even particularly interesting, as injuries go. I went to rummage in one of my three first-aid kits.

Why three? Well, the small one came from a small boat I once owned and is mostly the basics: Band-Aids and aspirin. At the other end of the scale is a monumental kit that Sir Edmund Hillary might have had Tenzing Norgay, his Sherpa, hump to the top of Mount Everest. That kit was from my 40-foot cruising boat, and there’s stuff in there I wouldn’t know how to use, from tooth-repair goop to a scalpel.

My medium-size kit, left over from an Olympic sailing campaign, had what I needed: adhesive suture strips. These strips are the poor man’s emergency room. They bind a cut without stitches. I stuck one on her wound and, with great professionalism, applied the perfect Band-Aid.

She asked where I learned the technique. The answer was, of course, on boats.

It is rare if troubleshooting or DIY on a boat doesn’t result in a barked knuckle (the wrench slipped off the nut), a cut (engine rooms have edges that are magnetized to attract soft skin) or scrapes (raw fiberglass is as abrasive as a metal rasp).

I was intrigued by a report a while ago about a yacht returning from Bermuda, where one of the crew slipped and whacked her head on a stanchion, opening up a flap of skin with considerable bleeding. After being unable to stanch the bleeding, the crew called the U.S. Coast Guard, which, with the usual skill and heroism, airlifted her to a hospital.

What particularly caught my attention about that story, however, were the yachts that stood by to offer help. One had a doctor aboard, and he was clearly my kind of doctor. He couldn’t transfer to the boat with the injured woman, but he provided medical advice by VHF radio on how to control the bleeding.

His advice? Duct tape.

Layers of duct tape were applied over the wound, and the blood flow ceased. I secretly smiled because I’ve used duct tape to bind my own wounds at one time or another. Nobody needs years of medical school to come up with that solution.

Boating is not generally a blood sport, but every piece of wire aboard seems to have a meat hook that finds soft skin, and you only forget once to keep your thumb clear as you close the heavy foredeck hatch.

On one long-distance sailing race, I was the designated medic, and I had to stitch up the hand of a crewmember who forgot to let go of a heavily loaded line when he released it from the cleat. I had actually trained for just such an occasion by sewing up a sliced orange, assured by our family physician that the practice was exactly like the real thing.

Well, it’s not. For one thing, the orange is neither jumping around nor screaming.

One time, I was considering a used boat and poking around the engine room when I noticed several brown stains on the hull side, right where I thought the engine might be throwing oil. When I asked the owner about the stains, his curt answer was, “Bloodstains don’t come out of gelcoat.”

True enough. I’ve left my mark on a lot of otherwise pristine white engine rooms while doing hasty troubleshooting or something as simple as oil changes. Trust me on this one: Oil filter wrenches bite. With sharp teeth.

A couple of weeks after the tin can incident, my wife came into my office and held up her thumb. “Look at this,” she said. “It’s completely healed, and there’s no scar. You’re amazing.” She just might be ready for duct tape doctoring next time.