THE AIR HOG
by Bruce Chadwick MA, M.Div.
Copyright May 2020
Perhaps you’ve heard of the “air hog.” This is the diver on the boat who runs out of air first, and usually way before anyone else. He is also the person who has difficulty finding a dive buddy. After all, who wants unused air in their tank because they were forced to chaperone an air hog to the surface? So what causes the air hog and how can he remedy this shameful reputation?
Before we come down too hard on the air hog, we should remember that all of us at one time or the other were probably air hogs. It’s a simple fact that when a person is excited, nervous, or unsure, one’s heart rate will increase. With this usually comes fast and shallow breathing. Unfortunately in scuba, getting out of breath and having increased heart rate are the culprits that quickly burn air supply and reduce dive time.
Divers should learn to breathe slowly and practice the slow breathing technique on every dive. Slow breathing decreases turbulence, which makes it easier for air to move through the windpipe. As well, divers should learn to breathe in and out deeply. This helps to minimize air loss due to dead air space.
Also as they breathe in full lungs of air, divers should practice keeping the air in their lungs for a moment before exhalation, to give their body time to absorb as much oxygen as possible. This is not a violation of the first rule of scuba, which is to always breathe continuously and never hold one’s breath. Rather this is breath control and the mark of an experienced diver.
Lastly, divers should move slowly, deliberately, and leisurely through the water. They should take their time and enjoy their surroundings. They should also maintain good trim, secure gear so it doesn’t dangle, and learn to cut though the water like a fish. Put together, all of these factors reduce diver air consumption and maximize dive time.
PUT ANOTHER DOLLAR IN
by Bruce Chadwick MA, M.Div.
Copyright November 2021
Water was once a mystery,
Cold, blue, untold history.
Man’s curiosity under its waves,
mysterious secrets, untold raves.
Then came PADI and Open Water Diver.
It only took time and more than a fiver.
Knowledge and skills, master, and do,
It worked together, and man dove the blue.
Then came equipment, the regulator and tank.
He bought jet fins and took money from the bank.
He stretched into his wetsuit and into the water he went,
He geared up proper and never got bent.
Just put another dollar in and sign the waver.
Read the book and Advanced you’ll savor.
Surely this was enough, for his skills were just fine.
He dove with his friends and his buoyancy did shine.
But what would happen if he encountered a hitch?
Rescue Diver status might solve that glitch.
So more money came due and Rescue skills to learn.
He gained more knowledge and experience in return.
Then they wanted pool help and some at the lake.
Divemaster he thought, but more funds it would take.
Physics and Physiology was what he then learned,
and professional diver status he then earned.
Surely this was enough, for he was now mostly poor,
but classes, students, and pool, it just opened the door.
When he thought about his choices, and pondered in concern,
His love for the sport just answered back in return.
But had he reached the pinnacle for his desire to dive?
Only Instructor was left, and that wasn’t his drive.
His desire was to get wet, not scuba to teach,
but they promised him riches if Instructor he reached.
He pondered and thought and finally did say,
“An Instructor I’ll be, I’ll start training today.”
He studied, memorized and the IDC then attend,
all yet for another PADI examination again.
So now he teaches scuba with passion and reign.
Some think he is smart, and others insane.
Despite all this, his students are his kin,
But he never fails to remind them, . . .
put another dollar in.
DON’T THREATEN US WITH YOUR SORCERER’S TRICKS LORD VADER!
by Bruce Chadwick MA, M.Div.
Copyright January 2022
Yes, you can laugh underwater. Or at least chuckle through your regulator. One such occasion came years ago when I was helping at the Boy Scout Sea Base in Islamorada Florida, a high adventure facility of the Boy Scouts of America. Several of us as Instructors and Divemasters had entered the water from the boat and descended to the bottom of Molasses Reef. We were the precursors before the adolescent Scouts began their descents.
However as the giant herd of young Scouts began dropping down through the water to the rendezvous point, and flailing around like startled bats scurrying out the belfry, suddenly there were no fish! It was if the fish looked up to see this gigantic flock of ominous cloud descending toward them and they responded “Holy mackerel! What the heck is that? I’m out of here!” I doubt there was a fish within 50 yards of the group. I guess we were a potential threat. It’s obvious the fish wanted nothing to do with us.
It’s a natural instinct for animals to flee potential harm. This includes aquatic life. So the moral of the story is simple. The divers who want to see fish are the divers who don’t pose a threat and scare them away. Divers should swim slowly, efficiently, and seemingly effortlessly through the water. Divers who are trim, neutral, and deliberate don’t pose much of a danger, and fish treat them accordingly.
DIVE! DIVE! DIVE!
by Bruce Chadwick MA, M.Div.
Copyright April 2022
Any sport or human endeavor has its challenges. Many of the trials come initially as one learns the basics. Unfortunately sometimes when divers don’t understand things, they are afraid to ask. However scuba techniques shouldn’t be secrets to be discovered and learned through trial and error.
As a new diver many years ago, I had a problem when it came to buoyancy and I was afraid to ask. And no, the problem was not what one would think. My ability to obtain neutrality in the water was just fine. I knew how to use my BCD to compensate the changes in water pressure due to depth, and maintain neutrality and weightlessness in the water.
As divers go down, water pressure increases and air in BCD’s is compressed. Divers become more negative. To compensate for the buoyancy loss and restore neutrality, divers add a little air to their BCD’s either by using their inflater buttons or by oral inflation. Inversely as divers ascend, water pressure is lessened and BCD air begins to expand. Divers dump air from their BCD's as they go up to compensate for gained buoyancy. The idea is not to exceed the one foot per second ascent rate protocol and hopefully avoid the dangers of decompression sickness.
However for me there was another problem. I couldn’t figure it out. While I always enjoy diving along on a reef with a group of experienced divers, sometimes a challenge would raise its dreary ugly head. It was the hideous monster known as the terrifying brain coral.
The puzzling part is that the other much more experienced divers didn’t seem to mind the beast. As they swam toward the coral, as if by magic they would rise effortlessly over the coral. It was if some unseen supernatural force gave them a lift. Then as they swam and crested the top of the coral, even more mysteriously the force would seemingly move them back down. They just never struggled to swim up and over the coral.
Not me. I would have to swim around the coral or collide. I knew if I tried to swim over, I would flail my arms and legs and look like banshee on a terror attack. Other divers would know I was a novice. Still despite that hall of shame, I knew I would never touch the coral. The beast would not meet its death because of my brutality and inexperience.
Still, what was the mysterious secret that allowed the other divers to swim, rise effortlessly up and over the coral and then back down again apparently without even trying? Later I discovered their secret and I couldn’t believe its simplicity.
For sailors to make their submarine descend, they flood their air-filled ballast tanks with water. As the air is pushed out, submarines become negative and the machines begin to sink. When sailors want their submarines to ascend, they pump air into their submarine’s ballast tanks to push the water back out. Submarines become positively buoyant, and the machines begin to ascend.
The divers on the brain coral were pretending to be submarines! They were using their lungs like ballast tanks. As they swam along neutral in the water, they breathed in and out slowly and deeply, the normal characteristics of an experienced diver. To rise over the coral as they swam toward it, they would simply take an extra-large breath of air into their lungs and hold it momentarily. This made them a bit buoyant and cause them to rise as they swam up over the coral. As they pinnacled the top of the coral, they would exhale deeply and hold it for a moment to become somewhat negative. This would cause them to descend as they swim back down the backside of the coral to continue along their merry way.
It is important for new divers to understand that this “lung ballast tank” technique is not a violation of the fundament rule in scuba, “Always breath continuously, and never hold one’s breath.” Divers who hold their breath as they ascend to the surface of the water, do so at their own peril. They risk the dangers of lung overexpansion injuries and decompression sickness. Fortunately there is a big difference between holding one’s breath and using one’s breath to enhance buoyancy control to help swim over hideous creatures like the dreaded brain coral.
TOO BLIND TO SCUBA?
by Bruce Chadwick MA, M.Div.
Copyright May 2023
In the ideal world, all divers would have 20-20 vision and use scuba masks only to provide the air space needed so that things don’t look fuzzy underwater. Unfortunately it is estimated that nearly 70 percent of Americans aged 18 and over need some form of vision correction, including eyeglasses, contact lenses, and/or vision correction surgery.
With modern contact lens technology, many divers wear contact lenses while diving with their scuba masks. However it is important for divers to use soft contact lenses that are gas permeable. Since there are considerable pressure changes that occur while scuba diving, there is the possibility of gas build-up between hard contact lenses and the cornea of one’s eyes. This may form one or more air bubbles which will result in vision distortion.
But what about divers who wear eyeglasses and cannot wear contact lenses? The solution for some divers is to use inexpensive stick-on plastic disk type magnification lenses. While some magnifiers are designed to be adhered to masks permanently, most are removable and designed to be adhered to the inside of scuba mask lenses temporarily. However these magnifiers mimic reading glasses and as such, generally only work for individuals who are far sighted and only need reading glasses to see up close. Unfortunately too, magnifiers can become loose and wash away. They are also limited in magnification power and not generally customizable to individual prescription needs.
Fortunately there are manufacturers who specialize in making prescription scuba mask lenses. Some companies even make scuba mask lenses with bifocals as well. Companies that make mask lenses can make bifocals for the prescription scuba mask lens. However the prescriptions one uses for their eyeglasses may not match the prescriptions needed for their scuba mask. Why is this?
Most people who wear eyeglasses become accustomed to a standard distance of their glasses from their eyes. If eyeglasses are worn too close to the eyes, or conversely worn further down the nose and too far away from the eyes, these positions change eyeglass focal lengths. This results in changed, distorted, and often blurry vision. In scuba, rarely are the distances between a diver's eyes and their eyeglasses the same as the distances from their eyes to their mask lenses.
Prescription scuba mask lens manufacturers often say, "Send us your eyeglasses prescription and we will make you mask lenses that compensate for this focal length change." This would be great if this was always true. The fact of the matter is, such “compensation” is usually only a guess and rarely is the guess completely accurate. Unfortunately the only way for a diver to truly determine the right prescription scuba mask lenses is “trial and error.” Now, what the heck does that mean?
An ideal way to choose the correct prescription lenses is to go to a scuba shop that sells prescription mask lenses. Divers should then put on a mask that has no lenses. Then it is a simple matter of holding-up various prescription lenses to the mask openings until one can see.
Or some of the larger scuba department stores may offer a large array of masks on display with prescription lenses in them. A diver simply tries on various prescription masks, keeping one eye closed at a time, and determining proper prescription strength lenses for each eye. The store then puts the correct prescription lenses in a mask that the customer then purchases.
Finally, there are also lens prescription dive mask inserts. These are separate pieces that mount to the inner lens of one’s scuba mask using various suction cup or bracket systems. Usually these only work with one piece “shield” types of lenses, rather than masks that have two separate lenses. Dive mask inserts aren’t as convenient as actual prescription scuba lenses, but certainly they do work.
Having a scuba mask with correct prescription lenses make all the difference in the world when it comes to seeing underwater.