OPEN OR CLOSED?
If you choose the open-circuit route to technical diving, you develop the skills and techniques you already have. Closed-circuit diving, however, is a new world. When you start diving a rebreather, it’s best to adopt the that you are learning to dive all over again, and keeping your mind entirely open to new ways of thinking and doing things.
If you’re hoping to graduate eventually to very deep diving using mixes heavy on helium, then closed circuit really is the way to go, because the quantities of helium required for very deep open-circuit diving make it extremely expensive.
Yes, rebreathers are expensive to buy, but once you become a deep trimix CCR diver, you earn back your investment very quickly, because your helium cost is far, far lower than it would be if you did the dives on open circuit. In Europe these days, it is rare to see open-circuit divers on the deep-diving boats.
You’re going to have to buy more gear, even if you don’t choose the closed-circuit route. You will need two good regulators for your back-gas, and two more for your decompression gases.
Other essentials include a harness and wing for your double cylinders, submersible marker buoys, reels, cutting tools, slates, waterproof tables, a multi-gas-capable computer and a dive-timer.
A LITTLE ADVICE
Don’t buy without expert advice. Technical diving is challenging and rewarding and it can take you to places on our planet seen first-hand by very few. But you have a lot to learn before you get there, so prepare for a lengthy journey.
There are several levels of training to pass through, and the courses only introduce you to the concepts and give you a little practice. So take it slowly and don’t let anyone rush you.
Do plenty of diving between levels to assimilate the new techniques and acquire expertise before moving on to the next level.