My review of the TDI Extended Range Course

As a technical diving intern, I often help in courses conducted by Blue Label instructors. This gives me the chance to get to know their individual styles of teaching and adds perspective to diving.

I recently completed TDI Extended Range with instructor Ben Capitaine and am now comfortable planning and conducting every part of a deep air decompression dive. Beyond the course, I got to know my instructor Ben Capitaine a little more. He remains humble about his past, but has been heavily involved in a variety of diving activities for most of his life. This was clear in the course, when considering how many things potentially could (but didn’t) go wrong in our deep technical dives.

I’ve had instructors with, in my opinion, an underdeveloped understanding of the physiological principles underlying diving. This was not the case with Ben – the classroom session that began my ER course expanded my knowledge and made it applicable to the dives we’d be conducting. In particular, I learned how to plan dives using Ratio Deco. This is an “on the fly” method for planning deco with minimal reliance on the software modern divers often favor.

Ben provided resources for me to pursue my own research as well, including texts by Bret Gilliam and Bruce Wienke. Many technical diver will recognize these authors as authoritative educators within the field. I used the books to compare decompression models, and to gain a better understanding of something that often causes debate among tech divers – deep stops.

Ben gave me the option of diving either sidemount or twins for the duration of the TDI extended range course. Because I’ve had more experience in sidemount and am always eager to try new things, I opted for a back mounted twinset. We spent time configuring gear and discussing advantages and disadvantages of different configurations.

The first pool session was no piece of cake. My dive skills with an unfamiliar twinset were not where they need to be. Although a recreational diver may get away with a subpar performance, Ben would not have it from me. He didn’t hesitate to say exactly what needed improvement, and we repeated valve drills until I was familiar and practiced enough for technical diving. A student technical diver is not guaranteed to pass the course if they cannot perform, and passing under qualified students is potentially unsafe.

A shaky start was quickly corrected with practice. The TDI ER course has a minimum of 4 dives with total bottom time of 100 minutes. Ben and I conducted 8 boat dives of at least 50 minutes apiece over three days of diving. These were filled with skill practice related to all aspects of diving. It’s not part of the course, but because Ben identified my ocean navigation skills as an area for improvement, he gave me extra instruction and allowed me to take the responsibility for this important aspect of the dive.

The final day included dives planned and conducted without help from Ben. I was responsible for the deco schedule, gas, and gear logistics for two consecutive deep dives. It forced me to consider many aspects, including what-ifs involving deviance from planned deco and lost gas scenarios. Our 48m dive would be my “check-out.” If I was able to adhere to a controlled plan and conduct the dive without major problems, I’d be qualified as an Extended Range diver.

Ben Capitaine - Technical dive instructor and maritime expert
Ben Capitaine – TDI extended Range Instructor

The TDI extended range dive went almost according to plan. When I tried to deploy an SMB during our 12m stop, the spool jammed and I was forced to let the SMB go or risk rapid decompression. Luckily, I had a spare SMB to deploy and did so without incident. We made it back to the boat safely, not having broken decompression or deviated much from our dive plan. This meant passed the check-out dive – Woohoo!

ER with Ben was the most challenging technical diving course I’ve taken. This made it one of the most valuable and certainly the most rewarding. Divers at this level must be able to handle the task-loading and decision making that goes into diving activities with real danger. I had many chances to practice my skills with Ben and, at the end of the course, am a more competent and experienced technical diver.

Thanks, Ben, for a fantastic experience!