Curious about technical diving? Underwater photographer Don Silcock shares his experience of starting training in technical diving later in life.
Don Silcock with instructor Chris Gamblin and dive buddy Sab O’Hara after a successful dive on sidemount to 45m.
Contributed by
Like many things in life, my technical diving itch began as a small curiosity and slowly grew into something much more compelling. It all started during the pandemic with an innocent question about the GUE training a friend of mine had recently completed.
Her answer was both honest and intriguing: It had been challenging but incredibly rewarding, and it left her wanting more. Sure enough, before long, she was learning to dive with a rebreather and went on to cave diving. That got me thinking!
At the time, I had been diving recreationally for over 40 years. I got my start with the British Sub-Aqua Club (BSAC) back when it could take six months of rigorous pool training before you were allowed anywhere near open water.
Things changed when PADI arrived on the scene, and BSAC evolved to stay relevant, but I always respected how thorough the original BSAC training had been. I eventually became an Advanced Instructor and then Diving Officer of the Awali BSAC branch in Bahrain, where I lived with my family in the late 1980s before migrating to Australia.
That Advanced Instructor certification was hard-earned, and it meant a lot to me. So, when my friend talked about her GUE experience, it stirred something familiar—the desire to challenge myself, to improve. But that had been decades ago. Now, approaching 70, I had to ask: Was this still something I should even be considering?
To find out, I went through full diving and medical checks, including a cardiac stress test. The answer came back the same across the board: You are good to go.
Getting started with GUE
Following my friend’s advice, I reached out to Duncan Paterson at Dive Centre Bondi in Sydney. Duncan, one of only a few GUE instructors in Australia, turned out to be one of the most genuine and supportive people I have met in diving.
On our first call, I led with what I thought was the elephant in the room—my age. Duncan asked about my fitness level, and I told him about my CrossFit routine and the clean bill of health from my doctors. He reassured me: You are definitely good to go.
Relieved, I signed up for the GUE Fundamentals course, or “Fundies”, as it is commonly known. There is a lot you can say about GUE, and many people do. But, to me, it is best understood as a complete system. It does not just teach you skills. It helps you figure out where you want to go in the multi-faceted world of technical diving.
My goal at that point in time was simple: become a better, safer diver, capable of staying down longer and going deeper on mixed gases. Rebreathers did not interest me then, and after nearly 40 years of marriage, I knew that cave diving was off the table.
No matter your background, every diver enters the GUE system through Fundies. For me, that meant setting aside 3,500 dives over 40 years, along with my BSAC Advanced Instructor and PADI Divemaster certifications, and starting fresh.
And so began the humbling experience of having my diving “credibility meter” reset to zero. Gone was the unspoken nod that I was the “experienced guy with the big camera who writes for a dive magazine”. Instead, I was the student struggling with frog kicks and a trim position that made Duncan wince.
What became clear after a few days was that I had become the diver I was through repetition and habit, not necessarily skill. Fundies stripped that away, and I came out the other side a far better diver. But I also saw clearly how much further I had to go.
Rec 3 and the valve drill reality check
The next step was GUE’s Recreational Diver 3 course, or Rec 3, which introduces twin tanks and stage bottles and qualifies you to 39m if completed successfully.
Rec 3 is where I hit my first serious wall. A key requirement is mastering the “valve drill”, where you must reach behind your head and operate the valves on your twin tanks. Despite physio and extra training, my shoulders simply were not flexible enough. Duncan was endlessly patient, even offering one-on-one sessions, but I could not complete the drill to standard.
GUE is clear: Unless you demonstrate full competency in all required skills, you do not pass. I respected that, and while disappointed, I paid in full and committed to returning once I sorted out my shoulder issues.
Switching gears: Enter TDI and sidemount
Post-pandemic, I resumed my travel-heavy schedule and started using the trim, buoyancy and finning skills I had learned from GUE. The difference was remarkable. I could hover horizontally, pivot effortlessly and make tiny adjustments while shooting. It was a game changer.
Still, the technical itch remained, but twin-tank diving was a non-starter. I already travelled with 50 kilograms of gear, and the additional bulk of manifolded doubles, backplates, wings and redundant regulators simply was not feasible.
That is when I started looking at sidemount. It offered double the gas and greater flexibility, with far less gear bulk.
Eventually, I found myself exploring the Technical Diving International (TDI) course offerings in Indonesia’s Gili Islands, a hub for tech diving thanks to deep local waters and a nearby recompression chamber in Lombok.
While the Gilis have a reputation as party islands, I found a great fit in Blue Marlin Dive on Gili Trawangan. My inquiry led me to Chris Gamlin, a British technical diving instructor, who turned out to be an excellent mentor and guide into the TDI ecosystem.
Full-on in the Gilis
After talking with Chris, I signed up for three back-to-back TDI courses: the two-day Sidemount course, followed by Advanced Nitrox, and then Decompression Procedures—collectively referred to as ANDP.
Transitioning to sidemount after decades of back-mounted tanks was strange. Suddenly, I had a tank on each side, two regulators and new muscle memory to build. It took time, but eventually I could monitor my gas and switch regulators in rhythm.
Advanced Nitrox took the theory up a notch. While the online materials were clear and logically structured, I still found myself reviewing lessons nightly to cement what I had learned. The drills ramped up the tension, too. Deploying an SMB at 35m while holding perfect trim is an excellent way to highlight any deficiencies!
But it was Decompression Procedures that truly felt like full-blown tech diving. We planned dives to 45m for 20-minute bottom times, with gas switches to 80% oxygen at 9m, and backup plans in case of missed stops or equipment failure.
In-water emergencies and mental stress
One key part of the TDI experience was emergency drill scenarios during deco stops. My dive buddy, Singapore-based Sab O’Hara, and I took turns leading these deep dives.
On my lead dive, it was my job to get all three of us to the ascent line, manage the stop schedule and execute the critical gas switch at 9m. It was right then that Chris morphed from helpful mentor into drill sergeant, running me through a rapid-fire sequence of emergencies.
It was intense task loading at its finest, in current, while hanging midwater on a decompression stop. But I got through it, and the sense of accomplishment was deeply satisfying.
Lessons learned
The most important thing I took from this journey was a profound sense of accomplishment, especially doing it all at my age, surrounded by divers often half as old.
Just as important was the realisation that I am now a much better diver. That speaks volumes about where I was before. Challenging yourself in a space where you feel comfortable can be humbling, but it is also where the most meaningful growth happens.
If there is one thing I learned, it is this: You are rarely as good as you think you are—and that is exactly why it is worth doing. ■
