WITH or Without?

This isn’t a story about forgotten gear. It’s about the invisible pressures that creep into our decisions as divers. For years, I’ve been teaching divers how to see the bigger picture. How to be open to these outside pressures and not fall victim. 

But everyone is subject to them, even the most practiced, even me. If you’ve never trained for this, you are at a major disadvantage. But practice doesn’t eliminate the possibility of a problem, it just gives you a better chance at perceiving the situation before it gets too bad. Understanding the Human Factors pre, during, and post-dive, can help you be in a mental place that turns a dive that just feels “fine” into one that is truly safe.

Last weekend, I headed up to the Straits of Mackinac for some wreck diving. The weather could not have been better. It was nothing but blue skies, flat calm water, no wind, and that perfect hint of fall in the air. On the surface, it looked like the ideal day to dive. 

But behind the scenes, the cracks were showing.

Another boat captain blew an engine and our captain helped out by taking his divers out in the morning. We shifted our departure time to accommodate the other group and that made my travel easier.

Now, I didn’t have to drive up at midnight after getting out of work late the night before. Although we moved to an afternoon charter, and the timeline should have been easier to deal with… we started later on in the day than previously planned. We forgot some equipment at home and we had to make some last-minute changes.

Immediately, while pulling gear out of the vehicles, we realized that we had left a very important oxygen bottle behind that was needed to drive a rebreather. Another teammate realized he’d left his instruments at the hotel and had to drive back to retrieve them. O2 sensors were not reading the way that makes you feel all happy inside, and now we needed to get that changed as well. Meanwhile, the clock was ticking. By the time everything came together, we were rushing to make it on the boat, and daylight was dwindling. 

None of this was dramatic on its own. We are all very experienced divers, we had back-up equipment we could use, and we’ve solved plenty of problems over the years.

But we were also diving on rebreathers, which were still relatively new to some of us. That combination of small problems, time pressure, and new equipment made me pause for a moment and think to myself, “Were we really ready to dive?”

That pause is something I remember Gareth Lock talking about in his Human Factors training. He uses the WITH model to explain what was going on.

W – Work Environment
The environment was working against us before we even got wet. Late departure, rushing to make the boat, and a schedule already shifted for another group. On top of that, once the scramble started, it became harder to slow down.

Shit! Where is my O2 bottle?
Has anyone seen my gauges???
It was starting to spiral a bit. 

I – Individual Capabilities
Yes, we were all highly experienced divers and some of us instructors. But with rebreathers… I was a newbie, we all were…. We were still building habits and comfort. Experience in one domain doesn’t always transfer smoothly to another, and overconfidence can mask blind spots. Not to mention, I was diving with some past students. Which meant that on top of everything, I had this pressure to be the elder and wiser diver who doesn’t make mistakes. 

T – Task Demands
Diving a rebreather has a lot of moving parts. There is a whole new level of pre-dive checks, system readiness, and making sure nothing gets skipped. Add in some gear changes, some forgotten equipment, and rushing through prep, and suddenly the task demand outpaces the margin for error.

H – Human Nature
And then there’s the human side. We’d driven all this way, the conditions were perfect, and the wrecks were waiting. Nobody wanted to hold up the group. Peer pressure, even when unspoken, makes it easy to rationalize shortcuts. Human nature pushes us to “make it work.”
So deep inside, you just want to say, “shut up and suck it up!” 

When “Success” Isn’t Success

It was great. Two glorious days on the Great Lakes. We pulled it off. And even if things had gotten out of hand, odds are we’d have gotten away with it. The dives would probably have gone fine, and we’d have called that a success.
But it wouldn’t have been true success. In reality, it would just be a good outcome from a poor process. And every time that happens, it reinforces the wrong lesson. Eventually, luck runs out.

The Value of a Pause

What made the difference was simple, we paused. We slowed down, reset, and took the time to ensure we were actually ready before stepping off the boat.
I went back to class, I was a beginner again.
We pulled out a set of wet notes and read line by line what comes next. That pause gave us space to do things right, not just fast.
When we did dive, it wasn’t with rushed uncertainty... it was with confidence.

Takeaway

The Straits of Mackinac gave us perfect weather this time. But human factors reminded us that perfect conditions don’t erase imperfect preparation. It’s so easy to blow things off and let a major “Fuck Up” sneak its way in. 

The WITH model Gareth describes (Work Environment, Individual Capabilities, Task Demands, and Human Nature) shows how little pressures can quietly shape big decisions. By pausing to recognize them, we turned what could have been a rushed, risky dive into one we were truly ready for.

The next time small problems start piling up, I’ll remember Mackinac.
M.A.C.K.I.N.A.C.
Maybe I’ll make my own Acronym for it. 
But more importantly, I’ll remember that readiness is more important than rushing.

Want to Learn More?

If this resonates, I can’t recommend Gareth Lock’s Human Factors in Diving training enough. You should join me up in Alpena next summer, I’m bringing him back to the USA. His work has changed how I look at every dive. All dives, not just the big, technical ones, but the everyday dives where invisible pressures show up.
If you can’t do the full class. At least do yourself a favor and go through the online Human Factors Essentials. It’s worth every penny. 
I’ve also been weaving these lessons into my Mott Underwater Method. When I work with divers, we don’t just talk about gear and skills… we talk about the human side of diving. We connect with discussions on how to recognize pressures, resist shortcuts, and make better decisions under stress.
If you’re curious how that applies to your own diving, reach out. I’m always open to the conversation.

OK, It's Your Turn

I’d love to hear from you:
Have you ever felt pressure to rush a dive when small problems started adding up?
How do you personally decide when it’s time to pause or even call it?
What habits help you keep your process strong, even under time pressure?

Hit Reply and share your thoughts—I read every message.