A few days after posting my thoughts on the OTS Guardian, I figured I'd write up the day I actually got certified with it — because the quarry where I did my full face mask and dry suit training was an experience worth documenting.
The Setup
Quarry diving is different from open water. You're in a landlocked, flooded rock pit — usually with no current, no salt, and water conditions that can range from crystal clear to absolutely dismal depending on the time of year and the specific quarry.
This one was dismal. In the best way.
The water was lime green. Not slightly green — lime green. The kind of color that makes you stop at the surface and think twice. Visibility near the top was maybe 15 feet. At depth, less. The quarry dropped to nearly 100 feet at its deepest points, and once you got down there, you were diving in a green soup.
That's actually exactly what you want for a training day. If you can handle that, you can handle a lot.
The Certifications
I knocked out two in one day: full face mask certification and dry suit certification. Both done in the same quarry, same day, back to back.
The dry suit training matters even if you think you'll only dive warm water. Buoyancy in a dry suit is completely different from a wetsuit — you're managing air in the suit itself, which shifts as you ascend and descend. Get it wrong and you can rocket to the surface. The quarry gave us plenty of depth to practice the control drills.
The full face mask cert covered the skills I'd written about — mask clearing, emergency bailout to a backup reg, communication protocols. Doing those skills in green low-vis water made them feel real. This wasn't a resort pool.
Buddy Safety Check
Before every dive, you run a full buddy check. Non-negotiable. In low-visibility conditions, it matters even more because if something goes wrong at 80 feet in green water, you need to know exactly where your buddy's gear is without being able to see clearly.
The standard check I use — BWRAF, or Bruce Willis Ruins All Films if you need a mnemonic:
- • B — BCD — inflator working, deflation working, any leaks
- • W — Weights — weight system secure, quick release accessible, both buddies know how to ditch each other's weights in an emergency
- • R — Releases — all buckles fastened and accessible, tank band tight
- • A — Air — both tanks open, both check each other's gauge, confirm full
- • F — Final check — fins on, mask ready, computer active, nothing dangling
Do this every time. Even with someone you've dived with a hundred times.
Navigating Blind
Here's where it got interesting. Part of the training involved navigating without a compass — and at one point without my mask on — in water where you couldn't see much anyway.
No compass, minimal visibility, 60+ feet down. The quarry has some submerged structures and platforms but they disappear fast in that water. You're navigating by time, kick count, and feel.
What I learned:
Stay calm first. Low visibility triggers a panic response in a lot of divers — it's a claustrophobic feeling, especially when you lose visual reference to the surface. The instinct is to ascend immediately. That instinct can get you hurt if you ascend too fast or into something above you. Stop. Hover. Breathe. Orient yourself before you move.
Use what you have. Even without a compass, you have:
- • Your dive computer (depth, time, direction of ascent)
- • Natural light gradients — even in green water, brighter means shallower
- • The slope of the bottom, if you can feel or see it
- • Your buddy — stay close, use touch signals
Count your kicks. If you swam out for 40 kicks, 40 kicks back on the reciprocal heading gets you close. It's not precise, but it's better than random movement.
Don't let go of your buddy. In near-zero visibility, physical contact with your buddy is your primary communication channel. Hand signals are useless when you can't see them. Touch signals — squeezes, taps — keep you connected.
The no-mask navigation was the hardest. Your eyes are open but you're just seeing blur. You rely entirely on feel, buoyancy, and time. It's uncomfortable. That's the point — you're training a response pattern for when things go wrong, not when they go right.
After the Dive
BBQ. Nothing complicated. Burgers, the whole setup, a group of us sitting around after two dives of genuinely challenging water. That's the part people don't write about enough — the post-dive debrief over food where everyone processes what happened, what worked, what didn't.
Good dive community makes you a better diver. The conversations after the quarry dives taught me as much as the drills.
The Takeaway
If you're thinking about getting certified in something — full face mask, dry suit, rescue diver — don't do it in ideal conditions. Do it somewhere uncomfortable. The point of training is to build responses you can access when things aren't ideal. Lime green water at 100 feet with a full face mask and a dry suit that wants to flip you upside down is exactly the right environment.
Do the buddy check. Navigate without your toys. Get comfortable being uncomfortable.
Then eat burgers.
— Dr. Scott