What Is Deco In Diving?

Decompression diving, also known as deco diving, is a technical dive performed by experts trained to withstand depths of more than 60-100 feet. It involves making one or more stops during the ascent to allow the body time to safely release nitrogen or other gas. Decompression diving involves intentionally going beyond No Decompression Limits (NDLs) to achieve a longer bottom time at a given depth. This could mean spending an A decompression dive is any scuba dive where you descend deeper than 60-100 feet for longer than 10-15 minutes. Under these conditions, enough nitrogen is released from the diver’s body due to the reduction in ambient pressure experienced during the ascent at the end of a dive or hyperbaric exposure.

Decompression diving is when a diver is required to make one or more stops during their ascent to give their body time to safely release the nitrogen. The decompression of a diver is the reduction in ambient pressure experienced during ascent from depth and is also the process of elimination of dissolved gases. Decompression diving is when there is too much nitrogen in the body to be released during a continuous ascent. Pre-planned stops are necessary to ensure safety during decompression diving.

In summary, decompression diving is a technical dive performed by experts trained to withstand depths of more than 60-100 feet. It involves making one or more stops during the ascent to allow the body time to safely release the nitrogen or other gas.

What happens if you go into deco?

Arguably, ignorance is even worse than panic. It is common to hear divers on a boat complain after a dive that their computer is broken. On examination, it turns out that their computer is working perfectly. It is just flashing a warning about missed decompression stops. On the dive they just completed, they obviously went into deco without noticing and then ascended without understanding what their computer was showing them and ignoring their required deco stops.So, as well as remembering to stay calm and move slowly to a shallower depth when you accidentally go into deco, you also have to know how your computer works.When you go into deco, your computer screen changes. A new depth appears, usually 3m (10ft) or 6m (20ft), and there is a new time display. The new depth is your decompression ceiling you must not go above this depth until the reading disappears or changes to a shallower depth.The time displayed is either your decompression stop time or an indicator of the minimum time it will now take you to reach the surface taking into account both ascent time and stop time.

Every make of computer is different (as you can see in the two images below). There is no industry standard. You must know how to interpret your deco screen. Study your computer manual, look at the relevant images or graphics and memorise them.

This is time well spent. Trust me, if you see your computer’s deco screen for the first time when you are at depth with your brain befuddled by narcosis, you will have no idea what it is saying, nor will you be able to work it out quickly.

What does the term deco diving mean?

A deco dive is where the diver has gone beyond no-decompression limits, so they must make a longer/extra safety stop on their way to the surface because they stayed too deep for too long. In deep technical diving, this is planned for, but it is avoided in recreational diving.

When you begin your journey as a recreational scuba diver, you are likely to hear some words and phrases you do not know, and you might think the divers are speaking another language. Many words are scuba-specific, and there is a lot of scuba diving terminology that is useful to know if you want to become a scuba diver. We have made this cheat sheet for when you are unsure what the heck these scuba divers are talking about! Ready to get dive-lingual? Here is the scuba diving terminology you need to know.

Equipment. When it comes to scuba diving terminology, knowing what your diving gear is called and how other divers may refer to each piece of kit is essential. Here are the top diving equipment phrases to learn:

1. BCD/BC/Jacket: You will get to know thebuoyancy control device (BCD/BC/jacket) quite well during yourOpen Water Diver program. It is used to help you control and maintain good buoyancy while diving. You can add air into it, and release air from it to stay in the perfect position in the water.

Is Deco diving safe?

When a diver swims to the surface too quickly (a rapid ascent), the nitrogen can form tiny bubbles in the blood and/or body tissues, causing decompression sickness (DCS).

DCS may occur even if a person dives within the limits of their dive computer or decompression tables and even if they complete a safety stop.

If a diver swims to the surface too quickly, and holds their breath while doing so (a rapid breath hold ascent), the resulting reduction in the ambient pressure can cause their lungs to over-inflate. This can cause the lung’s tiny air sacks to rupture, allowing air bubbles to escape directly into the blood stream. These air bubbles can block the flow of blood to different parts of the body, which is called arterial gas embolism (AGE).

How do you get DCI?. Diving is the most common cause of DCI in Western Australia.

What is the 120 rule in diving?

The simplest form of dive bezel is used in conjunction with a set of tables that indicates the no-decompression limit for each depth. You set the zero mark (usually an arrow) opposite the minute hand, and as time passes, the dive time is shown on the bezel. Knowing the maximum time allowable against the maximum depth indicated on a depth gauge makes for a safe dive. There is an old and questionably reliable rule, known as the “120 Rule” that says if you subtract your max depth from 120, you’ll get your no-deco time. So an 80-foot dive gives you 40 minutes before it’s time to head back to the surface. In a pinch, sure, but multi-level diving and time spent at each depth also plays a factor.

The author with a Rolex Submariner on one wrist and decompression plan slate on the other.

A step beyond the simple elapsed time bezel is the so-called “no-deco” bezel, patented by Doxa in 1967. This double scale bezel takes the place of those clunky and not exactly waterproof tables, by engraving the no-deco limits right on the outer ring. Set the zero mark to the minute hand when you descend, and the scale indicates when to surface for depths from 60 feet (60 minutes) down to 190 feet (4 minutes). This bezel type was also adopted by other brands like Eterna and Heuer, and is mainly aimed at the sport diver, who is sticking to recreational depths and doing strictly no-decompression diving. Similarly, Citizen printed the no-deco limit scale on the rubber strap provided with its Aqualand dive watches of the 1980s.

Is deco diving safe?

When a diver swims to the surface too quickly (a rapid ascent), the nitrogen can form tiny bubbles in the blood and/or body tissues, causing decompression sickness (DCS).

DCS may occur even if a person dives within the limits of their dive computer or decompression tables and even if they complete a safety stop.

If a diver swims to the surface too quickly, and holds their breath while doing so (a rapid breath hold ascent), the resulting reduction in the ambient pressure can cause their lungs to over-inflate. This can cause the lung’s tiny air sacks to rupture, allowing air bubbles to escape directly into the blood stream. These air bubbles can block the flow of blood to different parts of the body, which is called arterial gas embolism (AGE).

How do you get DCI?. Diving is the most common cause of DCI in Western Australia.

What is deco mode diving?

A decompression schedule is a specified ascent rate and series of increasingly shallower decompression stops—usually for increasing amounts of time—that a diver performs to outgas inert gases from their body during ascent to the surface to reduce the risk of decompression sickness. In a decompression dive, the decompression phase may make up a large part of the time spent underwater (in many cases it is longer than the actual time spent at depth).

The depth and duration of each stop is dependent on many factors, primarily the profile of depth and time of the dive, but also the breathing gas mix, the interval since the previous dive and the altitude of the dive site. The diver obtains the depth and duration of each stop from a dive computer, decompression tables or dive planning computer software. A technical scuba diver will typically prepare more than one decompression schedule to plan for contingencies such as going deeper than planned or spending longer at depth than planned. Recreational divers often rely on a personal dive computer to allow them to avoid obligatory decompression, while allowing considerable flexibility of dive profile. A surface supplied diver will normally have a diving supervisor at the control point who monitors the dive profile and can adjust the schedule to suit any contingencies as they occur.

A diver missing a required decompression stop increases the risk of developing decompression sickness. The risk is related to the depth and duration of the missed stops. The usual causes for missing stops are not having enough breathing gas to complete the stops or accidentally losing control of buoyancy. An aim of most basic diver training is to prevent these two faults. There are also less predictable causes of missing decompression stops. Diving suit failure in cold water may force the diver to choose between hypothermia and decompression sickness. Diver injury or marine animal attack may also limit the duration of stops the diver is willing to carry out.

What does a Deco do?

The Deco REPLACES your router. One Deco must be connected to your Internet Modem (not Router) via Ethernet. The other(s) can be anywhere in range, but work even better if they are connected via ethernet. Alternately you could have the Deco in Access point mode rather than Mesh Router mode.

At what depth do you need to decompress?

What is a Safety Stop?. A safety stop is a standard dive procedure that is done in scuba diving for any dives below 10 meters (32 feet) This brief 3 to 5-minute pause at a depth of 5-6 meters (15-20 foot) is a practice which allows a diver’s body to decompress after time spent at depth.

What is the difference between a safety stop and a deep stop? A deep stop is a 30 to 60 second stop at 50% of the maximum depth of your dive, whereas a safety stop, as mentioned above, is a stop at 5 meters (15 feet) for at least 3 minutes at the end of every dive. A deep stop is not a substitute for a safety stop.

Why make a safety stop?. As you will or may have already learned in your beginner Open Water scuba diving course, breathing compressed air underwater leads to the accumulation of nitrogen in our bloodstream and tissue. When we surface after being at depth, the pressure decreases, and that same nitrogen begins to leach back out. This process is often referred to as “off-gassing.”

What does no deco mean in diving?

No Deco Time is the time you can stay at the current depth without entering decompression. The calculation of this time above 100 minutes is represented as 100+.

How deep is a deco dive?

What is decompression diving?. Decompression diving, or deco diving, means intentionally going beyond No Decompression Limits (NDLs) to achieve a longer bottom time at a given depth. This could mean spending an hour at 100 feet (30 m) or 20 minutes at 164 feet (50 m), depending on your dive’s objectives. There are, of course, limits to both depth and bottom time for tec diving. You won’t spend two hours at 330 feet (100 m) for physiological and logistical reasons, and even though you could probably spend three hours at 65 feet (20 m), you’d probably get cold, tired, or bored.

Going beyond your dive computer’s NDLs gives you freedom to do more on a dive. Perhaps you want to take your time exploring the engine room of a Japanese freighter at 88 feet (27 m). Maybe you want to do a wall dive to 164 feet (50 m) in Malapascua in the Philippines to hang out with the elusive thresher shark. Whatever the case, decompression diving can help you achieve both the bottom times and depths you seek.

Physiological aspects. Occasionally you’ll hear people say that “every dive is a decompression dive.” When you descend, you compress, and you decompress on the way up. Although that’s true, on a recreational no-stop dive, you directly ascend to the surface (save the safety stop). When decompression diving, you must periodically pause on the way up. If you don’t, you are at a much greater risk of decompression sickness (DCS). To explain, let’s investigate what’s happening to our bodies when we dive.

How deep before decompression sickness?

Preventing Decompression Illness. DCS. Recreational divers should dive conservatively, whether they are using dive tables or computers. Experienced divers sometimes select a table depth (rather than actual depth) of 10 feet (3 meters) deeper than called for by standard procedure. This practice is recommended for all divers, especially when diving in cold water or under strenuous conditions. Divers should be cautious about approaching no-decompression limits, especially when diving deeper than 100 feet (30 meters).

Avoiding the risk factors described above will decrease the risk of DCS. Flying or other exposure to altitude too soon after diving can also increase the risk of decompression sickness as explained in Flying After Diving.

AGE. Always relax and breathe normally during ascent. Lung conditions such as asthma, infections, cysts, tumors, scar tissue from surgery, or obstructive lung disease may predispose a diver to AGE. If you have any of these conditions, consult a physician with experience in diving medicine before you dive.

Treatment. The treatment for decompression illness is recompression. Early management of AGE and DCS is the same. It is essential that a diver with AGE or severe DCS to be stabilized at the nearest medical facility before being transported to a chamber.

What is the deco limit for dive?

For dives in the 5-18 minute range, screwing up the deco is not necessarily a life threatening event, and anything will pretty much get you off the hook. However, it is best to treat these dives as “minimum” deco requirement dives and use no shorting of the schedule. Beyond 20-30 minutes you are in the “mandatory deco” range, where you must not blow off the deco or you will likely be severely injured from it. If you really screw up on a dive like this, but are able to get at least 20 minutes on oxygen at 20 feet, your survival rate will be acceptable.

The mandatory range merely requires “correct deco”, not excessive of prolonged deco, just the correct shape and approximate time. It is here and beyond that you can start using the techniques outlined in my previous post. Maximum deco is outlined in an example of a dive that I did with JJ this year. It does no good, and actually more harm to go beyond maximum deco, both in terms of oxygen damage and in terms of how the tissues relatively load and unload. Spending too much time at intermediate steps will merely load up the wrong tissues and make the upper steps less successful.

Keep in mind in minimum deco that the body’s reaction to pressure changes is not necessarily instantaneous. This is why commercial divers can get out of the water from 40 feet, change out of their suit, and get into a chamber if they do so within five minutes. I do not know if this is till practiced in, but this alone should give you some clue as to why “minimum”deco is a must. Passing through the depth ranges on the way up too fast does not give the body’s tissues time to offgas into the blood stream. It takes at least two minutes for the blood to make a full pass through the body, and it takes a while for the gas to make it out. If you trap it, which is what happens when minimum deco is ignored, it will merely cause symptoms later when you are on the surface, subclinical symptoms, like tiredness, flu like symptoms, etc.