Tec Diving Overview
What is technical diving?
Technical scuba diving is defined as diving other than conventional commercial or research diving that takes divers beyond recreational scuba diving limits. It is further defined as and includes one or more of the following:
• Diving beyond a depth of 40 metres.
• Requiring stage decompression.
• Diving in an overhead environment beyond 40 linear metres.
• Accelerated decompression and or the use of variable gas mixtures during the dive.
Because in technical diving the surface is effectively inaccessible in an emergency, tec divers use extensive methodologies and technologies and training to manage the added risks. Even with these, however, tec diving admittedly has more risk, potential hazard and shorter critical error chains than does recreational scuba diving.
How long has technical diving been around?
In the early 1990s, several groups of divers around the world began experimenting with technologies for deep diving (beyond recreational limits) to explore both caves and wrecks. These communities united and emerged as “technical diving” or “tec diving”, which dedicated itself to this type of diving. Since then, tec diving continues to develop both in scope, technologies and agencies such as PADI TecRec, IANTD, IART, PSA, TDI to name but a few.
Why would I want to be a tec diver?
Tec diving has a little more risk sure and requires more effort, discipline and equipment. It’s not for everyone, and you can be an accomplished, avid top-notch diver your entire life without making a tec dive. That said, there’s a cadre of well connected individuals who visit places underwater that relatively few people on earth ever have. Many spectacular, untouched wrecks lie at depths well below 40 metres and deep reefs have organisms you don’t find in the shallows, it's not only the depth, it's the time. Some people enjoy the challenge and focus tec diving requires, others love being involved with cutting edge technologies. But for most of us the reason is simple - We are able to spend much more time at the same depth as a recreational diver due to the amount of air/gas we carry and our decompression requirement along with diving to depths of up to 100 metres!
Which is the best entry level course for me?
We at Bay Divers recommend one of two avenues into the realm of Tec Diving, either the PADI TecRec Tec 40 course or the IANTD Advanced Recreational Trimix (ART) course. There are pages dedicated to both of these but the basic differences to these courses are:
• PADI Tec40 course is permitted to be conducted diving recreational dive gear carrying a pony and stage cylinder although diving a twinset, backplate and harness is strongly recommended. We can hire you these if you don't wish to make that initial outlay straight away! The planning will be done using decompression software and dive computers to dive with no more than 10 minutes decompression using up to 50 percent oxygen. You'll dive to a maximum depth of 40 metres on air and execute your ten minute decompression schedule. You will learn all the skills to give you the foundation to make you a competent and capable tech diver.
• On the IANTD ART course you will dive on a twinset, backplate and harness from day one, we can rent your equipment if you don't yet have your own. You will also learn all the drills and skills to give you the foundation to make a competent and capable tec diver. There is more emphasis on planning on this course and you will not only use decompression software but also multi-gas switching computers. On day four you will plan and execute a 48 metre dive using trimix, using less oxygen than in normal air and less nitrogen, substituting these gasses with much thinner helium. You will also use a mix of up to 50 percent oxygen to execute accelerated decompression from a stage cylinder to terminate your dive.
Once you've done these courses, many decide that they've arrived at a level they are most comfortable with, others move on to 60 metre and 100 metre qualifications using different gas mixes and up to three side slung decompression cylinders containing different gas mixes to accelerate decompression. If this is not enough of a challenge then you can progress onto electronic trimix capable closed circuit rebreathers and Karl our lead instructor dives the latest European safety accredited unit - the JJ CCR, a 100 metre capable rebreather - a fine piece of dive equipment!