Along with the Sidemount equipment that is specialized, you will also need your typical wetsuits, fins, masks, computer, compass, DSMB and other necessary equipment.
At first, technical diving was not something that interested me. I can clearly recall chuckling to my self at the Tec divers I observed, and wondering why anyone would want to have more equipment under water. I love the feeling of freedom and closeness to nature that can envelope you in "the quiet world". Tom was a respected teacher who I felt it was important to share my experience in Tec courses with.
2 first-stage regulator, 2 2nd-stage regulator, an exposure suit with side pockets and a BCD sidemount. A diving spool, mask and a spare mask. Technical diving equipments. 1 long, 2.10m to 7.10ft hose.
Overhead diving professionals are allowed to use cave passages that were formed by millions of years worth of water erosion. They can be found thousands of feet away from the entrance. These sites are a treasure trove of beauty and tranquility, which was only possible because of the time it took to form them.
Sidemount diving offers additional air sources, as you can dive with two tanks, each one with an SPG regulator and a first stage. Sidemount diving is safer and provides little air-hogs, like me, with more air. Sidemount diving is extremely comfortable. You can put tanks on the surface, and there is no pressure on your stomach.
New gear means new techniques. Sidemount diving, even if it's simple, requires some new skills (easily learned).
Sidemount cylinder mounting was first used for cave diving. It has since become more popular in technical diving. They take the dual cylinders apart, one for each, and place them on either side. The diver can't breathe from either cylinder if the regulator fails, but this allows for easier access to valves. Sidemount diving gives the diver an increased horizontal profile and a smaller vertical profile.
Sidemount Diver Specialty may count towards your Advanced Open Water Diver certification. Ask your instructor for details.
To dive beyond 130ft, decompression divers should add some Helium to their cylinders. This will allow them to enter the realm of the seldom seen. Sometimes, the reefs and wrecks they visit are visited less often per year than astronauts to orbit the moon.
One of most significant changes to the equipment cave divers use since the beginning is the shift from using backmounted doubles towards sidemount. While a large number of cave divers are now sidemounting, it is possible that there are many more sidemount cave diver than backmount.
For dives past 130ft decompression divers blend some Helium into their cylinders and dip into the realm of the rarely seen. The reefs and wrecks they experience are sometimes visited less frequently in a year than astronauts to the moon.
There is a wide variety of equipment that is used by technical divers the biggest impact on the decision is the environment a diver is exposed to. Many cave divers prefer to use Sidemount which means, independent single tanks are mount to the side of the divers’ body and attached by clips on a D-Ring on the waist band on the harness and on the shoulder. This allows the diver to detach and don tanks to fit thru tiny restrictions and have a lower overall profile to go to places unreachable for divers who chose backmount. During multiple trips, additional tanks can be placed in a cave or a wreck to allow the diver deeper penetration dives and to pick up tanks when leaving the cave or wreck.
Sidemount regulators will be taught. Asidemount regulators can be used on both long and short hoses. Sidemount regs are marked differently to normal regs. This allows you to easily identify the tank that you are currently breathing from. In my training, I was given a swivel elbow to use as a regulator for my short tube. There will be 2 SPGs available - one each for each stage.
Initial pool sessions were hard. I felt like an openwater diver again, strapped in to the twin tanks trying to conduct valve drills. However, as we moved through the Tec 40 to 45 and 50 courses, our skills improved and we were able to enjoy the course. The most satisfying part of Tec diving is taking your skills, buoyancy, knowledge and awareness to the next stage. It is quite exciting to be able to manage life-threatening emergencies at deep water without having to climb to the surface (due decompression requirements). It's gratifying to execute your dive plan in military precision.
2-3 hours
Even with small cylinders, you can usually dive for 2-3 hours (rebreathers typically have two 2/3l cylinders or one 3/5l cylinder).