English language

How to pronounce dead-air space in English?

Full Transcript

Ladies and gentlemen, welcome to Divers Ready!. My name's James and on this channel
I use my years of experience and passion as a professional diving instructor to help make you a better diver.
So be sure to hit that subscribe button
click the little bell icon and you'll never miss any of our content. Now
I want to talk about full face snorkel masks today because news out of the Aloha State of Hawaii
suggests that there's a problem with these masks. The number one cause of death in Hawaii for non-residents ie tourists, is drowning. But on average
Hawaii suffers 17 snorkeling drownings per year. Last year
they had 14 and 5 of them involved snorkelers using a full face snorkel mask.
I want to be clear right from the start here. There are reputable manufacturers of snorkeling equipment who produce a full face snorkel mask
who've gone to take steps to make sure that these things are safe.
The main problem is with the cheap knockoff copy no brands that you can find for half the price of a brand named snorkel mask.
It looks attractive because who doesn't love a deal. Half price! Excellent!
But there's some things you really need to know about these masks. And I bought this one for about 20 bucks.
Later in this video I'm gonna be giving you five
safety tips that if you absolutely have to buy one of these masks for like your least favorite child or an
annoying niece or nephew, at least these tips may help to keep them safe.
But first let's have a look at some of the design flaws in these cheap knockoff full face snorkel masks. To help me compare and
contrast the design of this full face snorkel mask
I've also brought with me a
regular mask and snorkel, and I brought with me my full face scuba mask
which is an OTS guardian that I use for public safety diving and public safety diving instruction. Flaw number one is
the seal. On a full face snorkel mask the seal has to cover a greater area than a regular
snorkel mask because it has to seal all around the entire face, hence the phrase full face. Now reputable manufacturers, of course use silicone
but silicone is expensive
so if you're gonna buy a mask for 20 bucks
you're gonna get a PVC seal like this one has. Now the trouble with PVC is it's not as flexible of silicone
which means it doesn't form as good a seal. And because there's such a large seal area
that means it can create a lot of failure points. One review
I read for this exact mask before I purchased it said that even squinting under water causes the mask to leak.
Now you might be thinking James. Yeah, but you know occasionally my regular mask leaks as well, so it's not such a big deal.
That's fine,
but when this mask leaks
you can still breathe.
The whole design of this mask or what makes it so attractive to people is not having the mouthpiece in your mouth and you can
breathe naturally through your nose or mouth.
But the problem is even a mask such as this one with an orinasal cup inside a little separate compartment for your nose and
mouth cannot guarantee that water won't come into the breathing compartment. On the front here, it does actually have these two one-way mushroom valves.
However, they look to me to be incredibly flimsy and very poorly made.
So I'm not sure I would trust my ability to breathe on those two little
valves. Now the second fault that these masks have is the incredible amount of dead space in the mask.
What do we mean by dead space? Dead space is essentially a volume of air that is not
recycled with every breath. In other words, when you breathe out you breathe a portion of the same air back into your lungs. And
without any of this gear at all
we have dead spaces in our body everything from the lungs up the trachea, your mouth, your nose, your sinus cavities.
All of those are dead spaces in other words, when you breathe out you breathe back in the same gas with your next inhalation.
Now whenever you add snorkel gear, you're adding dead space
Okay this snorkel here, which I measured with water is about a hundred and sixty-five milliliters.
So that's how much dead air space you're adding to your
sinuses and all the cavities in your upper body. A full face scuba mask such as this one doesn't have such a problem with dead
space. Although, yes, there is a large chamber where your face sits every exhalation is expelled through the exhaust diaphragm in the regulator.
So like a regular scuba regulator when you breathe out, there are bubbles. You're not breathing that gas back in again. Yes,
there is some dead air space added, of course.
But you're cycling through a lot more air than you are with a cheap full face snorkel mask.
Reputable brands have come up with a system where there's a series of valves in the snorkel itself so you can only breathe in through
one portion of the tube and all exhalation goes out the other way and that air can't come back in.
You're still left with the problem of the gas that is free flowing around in the mask space
but that at least does something to increase the cycling of gas through the mask. This little twenty dollar version. No such feature
I'm afraid. It's just one solid tube. You saw me attach it earlier.
So every time you breathe in and out you're cycling a large portion of the same gas back into your lungs.
Why is that a problem?
So let me take you back to high school biology for a moment.
Human beings like nearly every life-form on earth require oxygen to survive.
We metabolize that oxygen to keep our systems going and we exhale carbon dioxide as a by-product . Now
we require a fresh supply of oxygen
so if we have a dead air space where we're constantly breathing in the same air
we just breathed out. The oxygen content is going to get depleted
which is exactly what has happened in some of these drowning incidents.
The victims have been breathing in and out and snorkeling around become drowsy and eventually lose consciousness
And those of you with fast minds will have already figured out that being unconscious
facedown in the water is a bad thing. Other symptoms of hypoxia include
hyperventilating. Your body feels like it's not getting enough oxygen so you start panting which exasperates the problem and panic as well.
And yes, for those of you that are still following in double-speed
panicking while you're in the water is also a bad thing. Last but not least the strap system on the full face mask.. ah, I
read the little two page booklet that I got with this mask and it said for best fit make sure that you tighten the straps
as much as possible. Now, here's the trouble if you tighten this strap as much as possible
it's very hard to get off in a hurry. A hurry, you know
like when you're panicking in the water because you feel like you're being suffocated. If you look at the full face scuba mask, all
the buckles here are quick release and whilst you do have to have a snug fit while you're wearing it
they're all very easy to get off in a hurry. I bought this mask as a prop for this video
I'm gonna return it but not before I've done a pool test with it to see how I feel actually using this but in the
safe confines of a swimming pool.
But if you absolutely have to buy one of these for someone you care about but not really very much
I'm gonna give you five tips now for the safe usage of a full face snorkel mask. Tip number one
go with the name-brand. One that specializes in making water sports equipment. Do not buy a cheap knockoff
copy for the sakes of saving twenty bucks.
If you look at the link that I bought this from and then under where it says
manufacturer you click on the manufacturer you can see the other things that they sell. In this case,
they sell car seat covers and oil diffusers
which is not really a pedigree in water sports equipment in my opinion. Buy from a brand who has a research and development department
within their company that specializes in designing water sports equipment. Do not buy this mask is absolutely rubbish
the build quality is shocking and in my opinion it's a deathtrap waiting to happen for the reasons
I just explained. Point number 2 never let anyone you care about snorkel on their own.
This is regardless as to whether they're using a twenty dollar full face snorkel mask or indeed a really good regular mask and snorkel
setup.
Even if you're watching from the shore a face down snorkeler in the water having a great time
snorkeling looks a lot like a face down snorkel or who has drowned. And I come from having had the experience
of pulling a snorkeler out of the water unconscious.
There was a near miss in Hawaii last year where a guy was only saved because he passed out
due to hypoxia from using a full face
cheapo snorkel mask and
his buddy who was diving a regular mask and snorkel was conscious to his problems and managed to pull him out of the water in time.
Point number three to avoid catastrophe if snorkeling with a full faced snorkel mask is never overexert yourself. Never lose your breath, never swim
too hard, don't use these things in strong currents. Relax.
Obviously if you're over exerting yourself, you're breathing heavier, which means you're burning more oxygen and creating more carbon dioxide
which means you can get to a hypoxic state faster. So never overexert yourself. Point number four is take regular breaks.
Try doing fifteen minutes in the mask and five minutes without it. Take the mask off breathe fresh air come out of the water
whatever you've got to do.
They're not really designed to be used for hours on end better that you use it for fifteen minutes and then take it off and
have a five-minute break breathing fresh air then to snorkel face down for hours and hours and increase your risk of going hypoxic.
Take regular breaks. Dnd last but not least point number five for a safe full face snorkel mask
experience is
don't be too proud to use a snorkel vest. That simple flotation device that goes over your head and wraps around your waist
we've all seen the airline's practice it, could save your life.
If you get tired, if you get cramped if you get caught up in a current that thing will keep you afloat.
Don't be too proud to use a flotation aide.
Well, here goes nothing.
So I've been swimming for about 15 minutes.
At a leisurely pace, at the pace
I would if I was recreationally snorkeling and I got to say it is getting really really hard to breathe.
I didn't really feel anything like, you know, I was gonna pass out or anything.
But I did notice that I'm, I'm sweating for a start which is you know
not normal when you snorkel, you should be cooled off by the water. I'm definitely struggling for breath.
Which, you know, shouldn't be happening or that leisurely pace after only 15 minutes.
There's something wrong with this mask, I'm telling you that for a fact there's it's not right
I shouldn't be feeling like that after 15 minutes of light swimming. You know and despite the fact I'm a big guy
I am in shape. I do hit the gym and I do play rugby.
So, aerobically there's nothing wrong with me and yet you know
even as a technical diving instructor I was struggling to use this piece of equipment.
So there's definitely something wrong. Ladies and gentlemen
don't forget to hit that subscribe button and click the little bell icon
and that way you'll never miss any of our content. And let us know in the comments below
have you had any incidents with these full-face snorkel masks?
Are you considering to buy one?
If you only take one thing away from this video ladies and gentlemen
it is please if you absolutely have to buy a full-face snorkel mask, don't cheap out on it.
Don't for the sakes of 20 bucks go with some of the could be potentially life-endangering. Go with a reputable brand.
Look up the manufacturer make sure they have a pedigree in making water sports equipment. My name is James.
This was your Divers Ready! mouthpiece Monday for this week. Dive safe. Dive often.

Ladies and gentlemen, welcome to Divers Ready!. My name's James and on this channel

Toggle Transcript

dead-air space::noun | Spocien Dictionary

dead-air space

noun

an unventilated area where no air circulates

Type	Words
Type of	area

Examples of dead-air space

dead-air space

With the small size of the tube and the dead air space inside, it is efficient.

From the dailyherald.com

Bubble-wrap, thanks to its trapped dead-air space, is a good insulator.

From the denverpost.com

The insulating dead air space they create will still help some even with the new sash kits.

From the orlandosentinel.com

People often think exterior storm windows must seal tightly to create an insulating dead air space.

From the dailyherald.com

Foam strips with adhesive backing on one side can be used to fill dead air space between the door and the frame.

From the kentucky.com

The film will create a partial dead air space around the windows, and this can significantly increase its insulation.

From the kentucky.com

A solid row of evergreens next to a wall can create dead air space, and consequently, a year-round insulating effect.

From the abcnews.go.com

At the microscopic level the basidiospores are shot off basidia and then fall between the gills in the dead air space.

From the en.wikipedia.org

That same week a second state inspection discovered a crawl space containing dead rats, rat feces and bird feathers in the plant's air filtration system.

From the chron.com

How to pronounce dead-air space in English?

dead-air space::noun | Spocien Dictionary

abandonment

Related words

Examples of dead-air space

Related

Subscribe to our Newslatter