Intro to Tech

DSCN5728Tech diving. It conjures up immediate images of divers festooned with multiple cylinders, computers, slates, and plunging to depths that normal recreational divers and even some commercial divers would balk at. It’s a temptation to many, but few pursue it as an avenue of training and development as divers. So when I was given the opportunity to take a TDI Introduction to Tech Diving course with New Depths Diving out of West Kelowna, I signed on to see what was going on!

The course ran over three days, and the main goal was to introduce us to the concept of technical diving, and some of the more common methods of technical diving. The class was composed of a mix of diving levels, ranging from fairly new divers to instructors. Our instructors were Dan Downes, the regional director of SDI and TDI in Canada, Dave Tomblin, on of the top rebreather instructors in the country, and Freeda Wilson, newly qualified instructor and experienced cave diver. Needless to say, we were in good hands. The first thing that was emphasized was that technical diving was not about depth. It was more about time. Time to explore, time to see more, time to do more. The instructors were confident and presented the basic info with ease.

Our dives were conducted at the Dog Beach, just south of Peachland. It was a good training location, with decent vis (about 6 to 7m), and the bottom was tiered, creating several natural training depths to go to. We maxed out around 18m, but it would be very easy to go deeper (like normal for most parts of Okanagan Lake). The substrate on the bottom was soft silt over firmer sand with a few patches of weeds, but was nothing to worry about with good buoyancy habits. The weather was good the whole time, and there was a very convenient pub just up the road with a good kitchen for lunch.

The three technical diving methods we were exposed to were diving with doubles, closed-circuit rebreather diving (which will be a post in of itself), and diving using side-mounted cylinders. We had been familiarized with these in the online learning section, during the classroom session, and then again prior to diving. For my dives with the open circuit scuba systems, I used a set of steel 130’s for the doubles, and then a set of aluminum 80’s for the side-mount. My dive harness/BCD was good to go for the side-mounted set up, but I had to switch to a Hollis harness for the twins. We also got into the habit of testing breathing mixture for every cylinder, a nitrox and trimix procedure that added to the safety of our dives, and set a good pattern of behaviour for the future.


The doubles were my first go, and I have to say, it wasn’t for me. I understand that doubles take a lot of getting used to, but I found the balance on them poor and the buoyancy characteristics made for a long, but uncomfortable, dive. I enjoyed the greater breathing mixture capacity, and the greater ease of use while diving. Unfortunately, I’m not the most flexible of people, so reaching back to manipulate the isolation manifold was unpleasantly more difficult than I was comfortable with in the event of an emergency. I can see why a lot of divers use this system, but I don’t think it’s for me.

The side-mounts were the second go, and by far the best of the course for me. After throwing on a bit more weight than usual to compensate for the buoyancy characteristics of a second aluminum tank, buoyancy was a breeze. Maintaining situational awareness on the contents of two tanks was a snap as well, and much less daunting than anticipated. There were a few minor issues, but nothing that wasn’t related to it being the first time on a new set up.

So, over all, I very much enjoyed the experiences of the Introduction to Tech Diving course. It was my first exposure to technical diving, and to the TDI side of the family (I’m an SDI DM). The entire course was predicated on experiencing and learning about what technical diving is about, and how to do it in a safe manner. Nothing was forced, there was no pressure to push past where the students were comfortable. This approach was perfect to the material, and we all came away with at least an interest in pursuing some level of technical diving. Unfortunately, time and events contrived against us, so I have one dive left to do to complete the course, something I’m quite looking forward to! If you’re curious about technical diving at all, I strongly recommend this course. The online learning component was thorough and presented information in a way easily understood. The classroom review and overview were good as well, leaving us with few questions about what we were doing for dives the next few days. Definitely two thumbs up and a great way to cap the summer off!

About the author

Graeme is a professional diver, qualified as a PADI and SDI Divemaster, DCBC 40m Unrestricted Commercial Scuba Diver, 30m Restricted Surface Supply diver, and CAUS Scientific Diver Lv.2. Graeme has an Associate Degree of Arts in Environmental Studies, where he focused on archaeology and physical geography, and an Advanced GIS certificate.