The Emergency Ascent
A diver's reaction during a runaway/emergency ascent is a matter life or death and statistically the amount of divers who run out of air is unnecessarily high.
A substantial amount of confusion could arise regarding which techniques work best when effectively dealing with a runaway ascent. This is simply because there are two separate methods, the ones applied by highly trained divers vs. those taught to inexperienced open water students. Though it is a good incentive for the rookie to become aware of how Emergency Ascent Training is applied on higher levels, its best to stick to your ranking - it could save your life.
This article touches on what first-time divers experience, where they make their biggest mistakes and outlines the basic recommended practices that should be adhered to after proper training has been undertaken, in order to deal with the situation as calmly as possible. Applying the techniques should not be done without the guidance of a trained instructor.
EAT for Rookies
The best way to prevent an emergency ascent is to prepare for not having to do one in the first place. Pony bottles, alternate air sources suited to the type and kind of dive and constant monitoring should cover the essentials.
- In the event that this does occur, the following practices are advised during open water training;
- Don't panic or inflate your BCD. This merely results in messy buoyancy and is your fastest ticket to a runaway ascent. The idea is dumping air, not accumulating it. Optimal buoyancy control is thus a given in controlling rapid ascent.
- Divers are required to keep their airways open and look up - also ensuring that you know the area you are about to surface is completely hull, diver and object-free.
- Open water training covers when to drop the weight belt at the right time.
- EXHALE gently. Controlled ascents are executed by continual exhaling - diving regulator in mouth.
- Basic EAT is generally confined to 9m. General consensus adheres to 'blowing' air out gently all the way up during the ascent preferably by a type of humming, or saying 'eeee', 'ooooo' or 'ahhh' - (not the panicky ahhh).
- Keep things as simple as possible. Untrained panic responses where techniques revolve around countering actions like breath-holding from being underwater and other reflexes from being out of air can result in life threatening injuries.
How the Pros do it
Seasoned divers such as navy personal are known to use fitness and control when applying themselves to practicing ascents without air until it comes naturally. There can be nothing more useful during a no decompression dive than knowing that a comfortable ascent is on the cards because you practiced it properly.
The problem with an untrained emergency ascent lies in unnaturally 'exhaling consistently' and sometimes resulting in air being forced out too early. This defeats the fundamental action of the purpose, whereas just 'looking up' with the airway open will facilitate the process of its own accord.
When your lungs expand upon ascent and you exhale continually, the air releases naturally - a fail safe ensuring no matter how deep you are - there's always enough air to make the ascent. It requires extensive practice to counter the urge to breathe – which is why the practice isn't encouraged in the realm of untrained divers.
Records of navy demonstrations in submarine escape training tanks by trained personnel applying advanced levels of rapid ascent controls include demonstrations up to 30 meters.
The decent takes place in a bell, the diver exits, takes a single one breath of air and then succeeds, through effortlessly releasing a constant natural stream of breath, to perfectly balance buoyancy and lung volume with ascent rate.
The whole process takes approximately 5min with no exertion, hypoxia or bends when executed properly.