Dangers of Carbon Dioxide (Hypercapnia) and Diving.

With the latest fatality from Ginnie Springs, we at Discover Diving would like to explain how Hypercapnia is a silent but dangerous part of diving and we wanted to enlighten you on this subject. Are you doing any of the things listed, that you may want to change, as you dive? Read this article and make sure you know you are a safe diver.

(This article quoted from scuba.about.sports)


Most scuba divers do not learn about carbon dioxide during the open water course. Because the likelihood of carbon dioxide-induced problems is almost zero when proper diving practices are followed, the topic is often skipped over in certification classes.

However, carbon dioxide levels in a diver's bloodstream can rise under certain circumstances, and the effects can be disastrous. This article is not intended to frighten, but merely to inform. When a diver understands the risks of high concentrations of carbon dioxide, he is less likely to engage in behaviors that may predispose him to those risks.

Carbon Dioxide and Breathing:

The body needs a small amount of carbon dioxide for normal body functions. One of these functions is respiration. When a person inhales, he breathes in oxygen which his body metabolizes to create energy. One of the waste products of this metabolic reaction is carbon dioxide, which is eliminated from the body when the person exhales.

Increasingly, it is the rising level of carbon dioxide in a person's bloodstream (not the falling level of oxygen) that signals the need for respiration.

How Does Your Body Maintain Safe Carbon Dioxide Levels During a Dive?:

A diver's body is constantly producing carbon dioxide, which it eliminates through exhalation. When a diver requires more energy, such as during moderate exercise, his body breaks down oxygen rapidly to provide that energy at a faster rate. This speeds the production of carbon dioxide. To keep the blood level of carbon dioxide steady, a diver's body increases his respiration rate to eliminate excess carbon dioxide, balancing its production and elimination.

Carbon Dioxide in a Diver's Body Can to Rise to an Unsafe Level:

Any factor that causes the concentration of carbon dioxide in a diver's body to rise to 45 mg Hg and above induces hypercapnia – a potentially dangerous excess of carbon dioxide. There are two situations in which this can happen.

• The concentration of carbon dioxide a diver inhales increases.
• A diver does not eliminate carbon dioxide as quickly as he produces it.

The Dangers of Hypercapnia:


1. Loss of Consciousness.

Carbon dioxide has an anesthetic effect on a diver's central nervous system. If the concentration of carbon dioxide rises to 75 mg Hg (depending upon the person), a diver may lose consciousness. Underwater, loss of consciousness is usually fatal – an unconscious diver generally loses his regulator and drowns.


2. Narcosis

The anesthetic properties of carbon dioxide at elevated concentrations can cause narcosis. Some of the common effects of carbon dioxide narcosis are the slowing of mental processes and the loss of dexterity. Only a very small increase in carbon dioxide levels is needed to produce these effects; carbon dioxide is four times more narcotic than nitrogen. In addition to producing narcosis on its own, carbon dioxide can also amplify the narcotic effects of nitrogen and other gases.


3. Oxygen Toxicity

The human body has a programming glitch. It uses the level of carbon dioxide in the bloodstream to determine how much oxygen the body needs. In normal environments, this works well – as the carbon dioxide level increases, so does breathing rate, carbon dioxide elimination, and oxygen absorption. The higher the level of carbon dioxide, the harder a diver's body works to absorb oxygen. Unfortunately, in scuba diving high levels of oxygen can lead to oxygen toxicity, generally characterized by convulsions that result in drowning. High carbon dioxide levels cue the body to increase oxygen concentrations, speeding the onset of oxygen toxicity.


4. Decompression Sickness

Many hyperbaric physicians now believe that high levels of carbon dioxide may increase the risk of decompression sickness. One scenario is that high carbon dioxide levels interfere with the transport and elimination of nitrogen in the lungs. If the body is working hard to eliminate and exhale excess carbon dioxide, it will not be able to eliminate nitrogen as efficiently as it would if the carbon dioxide were not present. High levels of carbon dioxide lead to elevated levels of nitrogen in the body, which increases the risk of decompression sickness.
Avoid Elevated Carbon Dioxide Levels While Scuba Diving:

The most common behaviors and situations that increase the carbon dioxide concentration in a diver's bloodstream are listed below. By avoiding these situations, a diver nearly eliminates the risk of hypercapnia.


• Improper Breathing Techniques

Hyperventilation: When a diver hyperventilates, he fills only a small portion of his lungs and fails to fully exhale. This creates "dead" air spaces - spaces in the lungs and regulator in which air with high concentrations of carbon dioxide are not fully replaced with normally oxygenated air. For example, the first few mL of air a diver inhales from his regulator is "recycled," air with a high level of carbon dioxide from his previous exhalation. A diver must inhale fully to get past this air and receive fresh air. If a diver does not fully exhale, some of the of the old, carbon dioxide-filled air will remain in his lungs and he will breathe it again with his next breath. The concentration of carbon dioxide in a diver's lungs and regulator "dead" air space increases with each hyperventilated breath, leading to an increase in the level of carbon dioxide in his bloodstream.

Skip Breathing: In an effort to reduce air consumption, many divers hypoventilate or skip breathe. This involves extremely slow breathing. The diver exhales fully and then holds his breath "out", keeping his lungs empty for a period of time before breathing in. Hypoventilation increases the carbon dioxide level in a diver's lungs. Skip breathing can be dangerous because of the risk of hypercapnia.

• Physical Exertion

On land, a person's body adequately deals with the increased production of carbon dioxide during physical exertion by raising respiration rates. Underwater, the excess carbon dioxide is more difficult to eliminate. The breathing resistance of the regulator and the greater density of inspired air at depth make it nearly impossible for a diver to increase his breathing rate to match strong physical exertion. Either the diver begins to hyperventilate, increasing the level of carbon dioxide in his lungs while the carbon dioxide level in his bloodstream also increases, or he maintains a slow and steady breathing rate which is insufficient to eliminate the huge excess of carbon dioxide in his body.


• Deep Diving Without Proper Instruction and Gases

Air and other breathing gases become denser as they compress with depth. The more dense the air, the more difficult it will be for a diver to properly empty and fill his lungs with each breath. The result is retained carbon dioxide in the diver's lungs, similar to the situations listed in "Improper Breathing Techniques" above. This is yet another reason for divers not to go beyond the depth limits of their certification level. Deep diving courses train scuba divers in proper breathing techniques and teaches them about the gas mixtures needed for deep diving. Proper training will help deep divers avoid the risk of hypercapnia.


• Poorly Functioning Breathing Equipment

Regulators that breathe "hard" or increase the resistance of breathing can increase the level of carbon dioxide in a diver's bloodstream. When breathing resistance increases, divers find it hard to draw a full breath and exhale fully. Again, this leads to unintentional hyper- or hypoventilation, which increases carbon dioxide levels. Keep in mind that some regulators will breath easily on shallow dives, but may be inappropriate at greater depths.


• Breathing Gas Contamination

In contemporary scuba diving, it is extremely unlikely to encounter contaminated breathing gas. Strict regulations governing compressor use have helped to standardize tank filling practices. However, if the intake of a compressor is close to the exhaust from an internal combustion engine or other source of carbon dioxide, the air from the tank may contain abnormally high levels of carbon dioxide. While a high level of carbon dioxide may not cause any ill-effects when the tank is tested on the surface, underwater the increased concentration of carbon dioxide may lead to hypercapnia. Carbon dioxide is an odorless and tasteless gas, but other contaminants from exhaust are noticeable. Smell and taste the air from a scuba tank before diving with it. Any unusual findings could indicate that the tank air is contaminated with exhaust or other pollutants which may be accompanied by carbon dioxide. Report strange odors and flavors to the fill station or dive shop and don't dive if you think the tank may be contaminated.
Signs and Symptoms of Hypercapnia:

One of the problems divers face when dealing with elevated levels of carbon dioxide is that the signs and symptoms indicative of an increasing concentration of carbon dioxide may be masked by the dive environment. For example, symptoms such as elevated breathing rate may be attributed to excitement or cold water. Symptoms like headache may be misattributed or absent due to the high partial pressure of oxygen at depth. Unfortunately, this means that the first sign of carbon dioxide toxicity may be sudden unconsciousness. Here are common signs and symptoms of hypercapnia.

• shortness of breath
• headache
• narcosis - confusion, slowed thought processing, loss of manual dexterity
• unconsciousness

Remember, Hypercapnia Is Avoidable:

Basic good diving practices can nearly eliminate the chance of hypercapnia. Hopefully after reading this article, you will be convinced to always . . .

• Use regulators appropriate for the depth of your dive
• Avoid exertion underwater
• Use proper breathing techniques
• Avoid deep diving without proper training, gear, and gas mixtures
• Smell and taste tank air to check for pollutants that may indicate an excess of carbon dioxide

Remember, knowledge is power. The more you know, the safer you will be underwater. Happy Diving!

The Wrecks of West Palm Beach W/ Little Deeper Charters. Written by Brad Tonner, PADI Instructor

The first of our dives on Sunday was The Corridor which is definitely one of the best dives in Palm Beach County. The corridor is composed of four wrecks (Mizpah, PC1170, Amaryllis and the China Barge) that line up to form an amazing 1700-foot drift dive depending on the current. The China Barge is the last in line on this amazing site, although most divers don’t reach it before needing to ascend. As a dive site, The Corridor is an excellent training site for advanced, deep, and wreck specialties.

Our second dive was The Danny. The Danny sunk February 22nd, 2013 just north of the Lake Worth Inlet due to the combined efforts of the McCauley Family, Palm Beach County Diving Association, and Palm Beach County Artificial Reef Program. This 130ft ice class tug sits in 85ft of water and is now home to Goliath grouper, tropical fish and new sponge growth.

Even though some of our divers developed motion sickness and were unable to complete the second dive, the dives were enjoyed by most. The Captain and crew of the Little Deeper Charter took us out in windy and choppy conditions and dropped us right in front of each dive spot so we were able to successfully drift on to the wrecks and conduct our advanced and wreck dives. With a small current we were able to drift over the dive sites while seeing a green moray eel, a couple of sea turtles and 2 bull sharks.

All in all, it was an exciting day of diving!!

Come join our dive center for our next charter trip. Check out the Facebook page or call the dive center to find out when the next trip is scheduled.

Blue Grotto, Williston, FL - February Check-Out Dives

Our newest addition to the dive center, Brad, was with the group this weekend for our Open Water class final check out dives and had this to say about it:



We completed openwater dives 1 & 2 Saturday at Deleon Springs with zero issues. Everyone executed the skills required in a very calm manner. Today we will complete openwater dives 3 & 4 at the Blue Grotto dive facility in Williston FL and if all goes as planned we will be heading home with 6 new PADI openwater divers!! We also have several PADI Advance and Enriched Diver students participating as well. We are anticipating a lot of fun and excitement today!!



Brian and I arrived at the Blue Grotto Dive Facility at 9:15 and slowly signed in our dive students and pleasure divers as they arrived. We had a group of 6 openwater students, 2 Divemaster trainees and 4 pleasure divers. After getting set up and completing the dive brief we headed down the stairs to the 74-degree water that was full of others divers and one soft shell turtle named Virgil.

The dives went well and we would like to congratulate Marissa, Justin, Eric, Christian, Maggie and Dan on becoming certified PADI Openwater Divers!!!.

Preston and John (Both certified Divemasters, looking to link up with Discover Diving Dive Center and become part of the family), pared up with Charity and Selina and completed two pleasure dives to 60’.

Afterwards, everyone shared their stories of the dives while breaking down their gear with the exception of Christian, Dan and Maggie who decided to enroll in the Advanced Openwater Diver course and went back in for their third and final dive of the day.

It was a great day for everyone and Brian and I got a chance to meet some great people and make some new dive buddies!!


Big thank you to everyone in attendance. It was a great time for all. Thank you Brad for sharing with us your experiences with such a great a class. We hope we have inspired someone else that wants to get into diving. If you ever get the chance to take classes and learn how to dive, even if we aren't your instructors, don't hesitate trying it. You won't ever regret it. It is such an awesome experience and a lifetime of enjoyment. Dive, Dive, Dive!

There is nothing worse then a blog that is old! I am fixing that right now.

I know we haven't been the most up to date on these things but that is because we have been busy teaching some awesome people like you, how to dive and doing some fabulous dive trips.



We started making monthly dive trips to Epcot. That's right, Epcot. DiveQuest is what they call it. The living seas, inside Epcot, where it's located. This trip has gotten more and more popular the longer we offer to do these trips. If you have not done this dive, it is a great experience, even if you just go once. Drop by the dive center and take a look at the video we have of the actual trip we first did in May of 2015. First thing they do when we are taken back stage is we get to see just how large this facility is. We find out what the different species of aquatic life eats and where that is prepared. They supply all of the gear so the only thing you need to do is get your wetsuit and booties on and meet the guide before you dive. They suit you up and take you to the descent line. Once you descend you will get to dive with sharks, rays, tons of tropical fish and the best part...you get to be part of Disney's "show" to all the visitors in the observatory. Children and Adults alike, get to view your dive from the large glass windows. The children LOVE interacting with the divers and love to watch you. We have gotten several of the kids to play Rock, Paper, Scissors with us as we swim by the windows. It is only 25 feet deep so you should be able to make your air cylinder last the entire 40 minute dive. Don't worry if you can't, Disney gets you topside and hooks you right back up with a new cylinder and your back to the dive again in no time. We get a bit of a break in price if you come out with our group, so if you have been thinking about doing this dive, stop by and sign up for the next trip we have going. You won't be disappointed!

Summer is almost here!!!

Tuesday, May 26th, join us for our first pre-summer dive trip to West Palm Beach. Should be an awesome day of diving. We have decided to use Little Deeper Charters for this first dive trip of the season. We are the only dive group on the charter for the day and we are hoping it stays that way. LOL We will post up pictures from this dive on our Facebook page so be sure to check that out.

Click here to connect to Facebook.

Just in case you haven't heard yet...Ryan is no longer with the shop. We parted ways in March 2015 and he has gone solo. Still doing his thing in the area for a little while. He is expecting his first child in late August or early September. Once his bundle of joy is here, he will determine where life will take him next. Any students that had Ryan as an instructor, you are still a Discover Diving Dive Center student so feel free to continue your diving with us.

The shop may start doing some offshore Daytona Beach dive trips this summer. We have been in talks with an instructor that has a boat and plans on doing some trips right here in Daytona. We will keep you guys informed of that, if and when it becomes available.

Discover Diving Dive Center has a new employee, Jenn.

She is only part time but would love to meet all of you guys. Stop and say "Hi" if you are in the area on a Tuesday, Friday or Saturday. She is likely going to be working these days, to help us out here at the shop. She is an awesome addition to the shop.

Friday, May 29th will be our first Epcot Dive Quest trip. Therefore, the shop will be closed so all of us can be involved on this There was a high demand for this dive adventure so we booked it and the trip was full within 2 days of announcement. We will definitely be hosting this trip again in August 2015. So, don't be too upset if you weren't able to join on this trip. You will have another opportunity to get to dive in Disney next time. LOL Of course, we will be purchasing the video Disney offers so you guys can stop by the dive shop to watch the fun!

St. Croix Diving with Ryan and Dan

November 3, 2014

Dive Site: Cane Bay Wall, St. Croix
Depth: 216’
Time: 63 minutes
Surface Temp: 82 Degrees

On November 3, 2014 I set off with Dan Weeks, for our Deep Dive off Cane Bay wall. Ever since crossing into the Technical Diving world, 200’ has been a huge goal of mine. Michele having been to 208’, I was planning on going Deeper. Dan and I planned the Dive to 216’.

We started our 250yard swim offshore and it became real. I was so excited, yet focused on such an awesome dive. We set off to our first gas-switching point which was 130’. At that point we switched from 32EAN to Air. We dove Air to our final Destination.

Upon Reaching 216’, We gave each other a high five, and took a few minutes to enjoy the view. There is nothing in my life that compares to looking up from 200’ underwater. We began our ascent, nice and slow. I shot a lionfish at about 185’ and immediately had a Black tip Shark come to investigate. I wouldn’t give him the Fish, not for a while at least, so he would stick around for some photos! Around 130’, when it was time to switch back to 32EAN, I kicked the lionfish off and got the video of the shark taking the lionfish. We never saw the shark again.

From there it was smooth Sailing, the majority of our Deco Obligations were fulfilled between 90’-130’. We took our time enjoying the beautiful Cane Bay Coral Nursery, taking note of countless Christmas Tree worms, A large Barracuda, schools of snapper, squirrelfish, Tangs, Filefish and butterfly fish. I could go on forever, if it’s a Caribbean fish, it was there.

In the End, we did 63 minutes total, after a beautiful dive to 216’. If you are interested in Technical or Sidemount diving, feel free to contact us at the shop for more information! We offer several different courses to get you involved with either!

Watch their video: Click here

Gary Kessler's Heroic Adventure aboard Underwater Explorers charter on March 16, 2014.

Just a little background information on Gary. He is a professor at Embry-Riddle Aeronautical University in Daytona Beach and a PADI Open Water instructor. Gary has been an active member of our dive center for some time now and we thank him for allowing us to use this story in both our newsletter and this blog.






Gary tells us his accounts of the events as they happened...

So, my captain's license rating is for inland waters -- such as Lake Champlain -- and I would eventually like a raise in grade to cover near coastal waters, but that means an additional 360 days on near coastal waters! Anyway, to that end, Kevin Metz from Underwater Explorers in Boynton Beach, FL said that I could spend a few days with him during my Spring Break this week.

Now, for more explanation -- Kevin runs a six-pack boat, meaning that he cannot have on board more than six paying customers. He is also allowed one crew member; in this case, a dive master named John. PLUS, he took me, as a captain-in-training. Today, we had a full complement of divers meaning that there were nine people on board. Today, per Kevin, was the first time that he has ever had nine people on his boat. Today was very windy and somewhat rough out on the ocean. No matter, out we went -- as did other dive boats -- and we made our 40 minute ride out to the dive site, which was a wreck sitting in about 105' with the deck at about 85'. We put John, the dive master, in the water at about 0905 to secure a descent/ascent line to the wreck. We put the six other divers in the water at about 0910.

At about 0930, the first diver -- a guy named Richie -- came back up and we picked him up. At about 0938, we saw other divers' bubbles approaching the surface, and I said to Kevin, "Ok, there are a couple of divers. No, three... four." As we watched them surface, one of them started slapping the water. Now, for you non-divers... the proper signal upon surfacing is to face the boat and put one or both hands on the top of your head, indicating the OK signal. Slapping the water means that something has gone terribly wrong. So, we see the slapping and my first thought is, "These people do not know how to signal a dive boat." Then, one femtosecond later, I realize "Oh crap, these people do know how to signal a dive boat" as I noticed that three of the divers were way closer to each other than would ordinarily be the case. As we approached the divers in the boat, Kevin and I could both see that one diver was being held up by the others and that he appeared unconscious. I immediately went below to grab the oxygen kit. By the time I got back to the deck, Kevin had swung the stern to the divers, and he and Richie had gotten the unconscious diver -- Micah -- on board. Kevin had ascertained that Micah was pulseless and apneic, which I also confirmed. I was on Micah's head by this time and turned to Kevin and said, "Oh, one more thing I forgot to tell you about myself. I worked 25 years on an ambulance."

Kevin returned to the helm to maintain control of the boat, what with the high waves, and to recover the other three divers. I taught Richie, in real time, how to do chest compressions (*not* the first time that I have done that in the field!). Anyway, every compression pushed more water out of Micah and I did some mouth-to-mouth although it wasn't that effective early on because of the water. [[ What we found out later was that Micah had been advised to start his return up the line when he was half-way through his tank at 1500 psi. Although diving Nitrox, one goes through your gas quickly at 90' -- I dove this same site with Kevin 2-3 weeks ago and I only got a 40-45 minute dive. Anyway, at about 70', Micah showed one of his buddies his gauge which showed 1000 psi. She signaled to go up and at 54' he signaled that he was out of air. Our guess was that he was anxious about some aspect of the dive and was just blowing through his air. Anyway, he signaled out-of-air and another of his buddies tried to give Micah his spare regulator but Micah wouldn't keep it in his mouth. Seeing that Micah was unresponsive, his two buddies made an emergency ascent from 54'. ]]

Anyway, after about 5 minutes of CPR, Micah started to respond(!). He was not responding to verbal commands but he was clearly breathing on his own and, of course, had a pulse. During this time, Kevin had called the Coast Guard. A nearby dive boat came to our aid to pick up our last two divers. Meanwhile, SeaTow had a rubber boat nearby and offered to take the rescuers in because he could go much faster than our dive boat.
By the time SeaTow got to us a few minutes later, Micah could squeeze his hand upon command, his hand grip was strong and equal, he could follow our voice, and I started taking vitals. SeaTow arrived, and DM John and I got in the boat with Micah, who was no longer dead weight. We kept him on O2 and monitored him and kept improving. SeaTow, indeed, made much better time than the dive boat! As we approached the Boynton Beach Inlet, both Coast Guard and Palm County Sheriff's boats were coming out and they were hauling -- both were at at least a 45 degree angle as they cleared the inlet; they saw us and got in line behind us as we went in to the sheriff's dock. By this time, Micah was pretty responsive, at least to name. He didn't know where he was but he did remember diving. We transferred him to the paramedics, and as they did their stuff, he was able to verbally answer questions.

About 25 minutes after we got to shore with SeaTow -- and the paramedics had already left -- our dive boat arrives. And, that, of course, is the beginning of a very long process!!! So, the event started at about 0940. It's now 1040. USCG, Palm Co. Sheriff, FL Fish & Game, and local police are there. We all get interviewed by all the cops. Media arrives and none us agree to talk on camera. USCG does an inspection of Kevin's boat and interview Kevin. Sheriff interviews Kevin. One by one, the agencies leave. It is now almost noon. John, Kevin, and me -- the crew -- are instructed to stay on the boat and await the USCG Safety Officer. AND, to not eat or drink, as we have to have a breath test -- which, BTW, must happen within two hours or as soon as practical. It's now been been closing on three hours.

Safety Officer arrives. We fill out statements and how try to find a cop with a breathalyzer. Although we are docked at the Sheriff's pier and there is a substation there, there is no sheriff to be found. Safety Officer tells us to go to any police station ASAP. During this time, Kevin had left all of the instruments on on his boat -- meaning that both batteries were dead and we couldn't start the engine. We couldn't get a charge right there so he asked a buddy to come give us a tow. So, we get the tow, back to the dock... and by now, it is 1530 and six hours after the event. We dutifully drive to Boynton Beach PD where we are told that no one can administer a breath test. We are told to try the sheriff. We call the sheriff's office and they tell us to go to the main station, which we do... a 25 minutes drive. We arrive and they say that we have to go to the adjacent jail. Jail tells us to talk to probation -- TOMORROW!!! It will be 24 hours after the event before we get our "within two hours" breath test!!! [[ In my opinion, if a breath test soon after an incident is so important -- and it could well be -- USCG or Sheriff should equip their marine units with a testing device. But, I digress... ]]

Anyway, the next day we also needed to get our drug test. We had 32 or 36 hours to get that done.
We have had no word about Micah's status but, as Kevin observed, "he was brought back on the boat dead and left the boat alive." Just fortunate, maybe, that today he had a ninth person on board!

Update: March 23, 2014 - The victim does not have any brain damage but there are some respiratory issues, although the expectation is that he will recover. The object lesson, obviously, is to watch our gauges!