Every technical dive is different, just like every technical diver is different. And technical dives can take place anywhere from the open ocean to overhead environments like caves and wrecks. However, the ABCDs of technical diving — Awareness, Buoyancy control, Communications and Discipline — are vitally important on every technical dive. Without even one of them, the accident risk is infinitely higher. Here we’ll examine each of these foundational skills in turn.
A is for Awareness
Knowing what’s happening with themselves, their teammates and the planned dive in general is essential on any technical dive, and teaching tech diving students about it is part of most training agencies’ core curriculum. TDI, for example, breaks awareness down into three subcategories — self-awareness, global awareness and situational awareness — which together lead to a diver displaying ‘true awareness.’
Self-awareness deals with the diver himself. Being self-aware starts before the dive. It includes, for example, checking your equipment, the dive plan and your state of mind to ensure that you are truly ready for this dive. On the dive itself, it’s about checking that you’re at the right depth for the right amount of time and thinking about nitrogen narcosis, to name only two aspects. After the dive, it’s about having a debrief and potentially making changes.
Global awareness is about the team and paying attention to how everyone else is getting on before, during and after the dive.
Situational awareness is about knowing whether the dive is progressing as planned and what should happen next. In practice, it means knowing how much more time the team has before they need to start ascending and whether you must make any changes to the plan.
Bringing these three types of awareness together creates truly aware, safe technical divers.
B is for Buoyancy Control
Do we really need to bring up buoyancy control when we’re talking about technical diving? Emphatically yes. Too many tech students sign up for their courses with less-than-acceptable and much-less-than-perfect buoyancy control.
When it comes to decompression diving, divers are expected to stick to their deco-stop depth with less than three feet (1 m) of variation, often laden with much more equipment than for the average no-stop dive. Adding equipment changes buoyancy, and if divers struggle with hovering motionless when wearing a single tank, a twinset is unlikely to help.
Achieving perfect buoyancy control on every single dive – never mind the equipment, conditions, dive buddies or anything else — should be every diver’s mission, both technical and recreational divers.
C is for Communications
Clear communication can be hard enough on land, let alone underwater. This is why divers use hand signals. Tech divers tend to have a few more than recreational divers, and many of them only use one hand.
One-handed communication is important when divers carry torches in open ocean and even more so in overhead environments. In these situations, one hand might be busy running a line or making contact with an existing line.
Understanding each other is so crucial that tech divers repeat their messages back to each other. For example, if the lead diver signals “let’s go up to 69 feet (21 m) to switch gas,” the team replies with exactly the same hand signals. Simply signaling ‘ok’ is not enough, as it doesn’t truly confirm that everyone has understood and agreed on the same action. Repeating the same signal makes it easy to clear up misunderstandings before they lead to problems.
Another step in the communications chain is touch communication — ‘talking’ to each other in low or no visibility. Students first learn about this skill during regular tech-diving training and perfect it during overhead-diving courses.
D is for Discipline
Remember the adage ‘plan the dive, dive the plan?’ Technical divers need to take this seriously.
Tech divers base their plan on how much gas they have and will consume in relation to their planned depth and time at that depth. This, in turn, determines the time and therefore the amount of gas required for decompression stops.
It’s crucial to stay within the plan, i.e. not exceed the maximum depth or the maximum time at that depth. Doing so might not only mean exceeding the amount of gas planned for the dive but also extend the deco time. This can again lead to a lack of gas here.
Discipline stretches much further than dive planning and includes looking after your equipment, keeping yourself fit and so much more. Many things that divers ‘get away with’ on shallow dives can have dire consequences on decompression dives.
While these ABCDs are far from covering each consideration that’s involved with technical diving, they are a great foundation on which divers can build.