Divester

SCUBA Theory: Swimming Better

Will O'Brien — 2007-01-10T18:43:00+00:00

Lately I've gotten a few questions from friends of mine who want to learn to swim better. I'm happy to help them - especially knowing that I only tweaked my stroke into decent shape in the last few years.

If you don't know how to swim at all, seek out some classes. They'll get you in the water and make sure you don't drown in the process.

If you're more like my friends, who haven't swam much since they were kids, then I've got a suggestion for you. Go take a look at Total Immersion by Terry Laughlin and John Delves. It's full of simple ways to improve your swimming. I found it very useful to read though it a bit, then head down the pool and focus on a particular aspect of my swimming for the session.

There were two concepts that really helped me. The first was called 'press your buoy'. This translates to keeping your chest under the water. Once you do, you'll find that the rest of your body floats much better. Staying on top of the water takes less effort, translating to more efficient forward motion. The second was swapping your hands. By always keeping a hand in front of you, your body is longer in the water. Longer objects travel through water with less resistance, again resulting in more efficient swimming.

I'm a firm believer that SCUBA divers should have decent swimming skills. If yours are a little rusty, the book is a great way to tune up.

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SCUBA Theory: Surface Dives and Water Entry

Will O'Brien — 2006-09-07T14:33:00+00:00

Filed under: SCUBA Theory

SCUBA Theory is following the wet sessions of a unique, semester(three month) long university level Advanced Open Water SCUBA class. Last week we got the fins out. Today we're getting into basic skin diving and SCUBA skills with surface dives and water entry techniques. Most open water courses don't teach all of these entries, so it's a good series to read up on if you are already certified.There are four surface dives and three water entry techniques that we teach in the wet sessions. pike, tuck, kelp and spread eagle dive. (Yes, I said spread eagle dive, not entry.) I'll go through each one - today you even get whiteboard action to help you visualize what's happening.

The pike dive is the first surface dive we teach. As you're swimming forward, you use your arms to pull your torso under water. Keep your legs straight and raise them above you. The weight of your legs out of the water will provide the downward force for the dive.

The tuck dive is similar to the pike. Again moving forward, use your arms to pull your torso under. The difference is that you tuck your legs up then stick them straight up in the air. Once more the weight of your legs out of the water will drive you down.

To perform the kelp dive, assume a water treading position and put your hands down - you can grab your shorts to make sure you keep them against your body. Use your feet to kick you up out of the water. At the peak, stop kicking and straighten your body. The weight of your torso out of the water will drive you down under. The point of this dive is to get under the water without tangling your arms in a kelp bed.

The spread eagle dive is like the kelp dive, but we use our hands to get up and go below the water. We press our hands down with the kick and once submerged raise them up to assist with the dive.

The first water entry we teach is the forward roll. The dive steps up to the edge of the platform/boat. Place a hand on the mask/over the regulator to keep them in place. The other hand is used to brace the mask holding arm. The diver crouches a bit and rolls forward into the water. No jump is needed, just lean a bit and let gravity do the job.

The backward roll is more challenging with skin gear than SCUBA. First we look over both shoulders to make sure we're clear of obstacles (boats, people, etc). Grab the mask with one hand to keep it in place. Tuck your legs up to you and your body weight will be shifted back enough that you'll fall backwards into the water. In full gear the tank makes this entry very, very easy.

The spread eagle or giant stride entry is very popular. When done properly the divers head should never go below the surface of the water. Again securing the mask/regulator with one hand, bracing that arm with the other. Standing at the edge of the platform/boat, the diver steps forward. All of the energy is used to step out as far as possible, not upward. The feet are apart at water entry, and they are scissored together to slow the descent into the water.

Those are all the skills we covered for the days water session. There are a few normal problems. Most people let their legs come apart during the pike and tuck dives. The backward roll takes some confidence - falling backwards isn't that natural the first few times. On the giant stride most people have to work on their timing to keep the head clear of the water.

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SCUBA Theory: Get your kicks

Will O'Brien — 2006-08-30T10:45:00+00:00

Filed under: SCUBA Theory

SCUBA Theory is following the wet sessions of a unique, semester(three month) long university level Advanced Open Water SCUBA class. Last time we hit the snorkels, today we're moving on to fins. We cover the basic kicks and then start bringing things together under the water.

With each session until now, we've added another piece of gear. For today, everyone will have mask, fins, snorkel and a weight belt. Dive shops usually require the student to furnish these basic items. For this class, we provide everything. We keep a selection of full foot fins for the students. Scubapro's full foot floating fins have served our pool sessions well for years. They seem to handle the chlorine very well and they're thick enough to take lots of abuse. (I personally prefer something with a slightly stiffer blade, especially when assisting students)

Our first kick of the day is the dear old flutter kick, but we start out with the students facing up. In full gear this makes sense, but considering that several students are still getting used to the mask/snorkel combo it's a good way to start out. (Each class varies, today I saw plenty of people spitting out their snorkels to get more air.

The dolphin kick is next. It's an air intensive kick, but it's very powerful. If you're not familiar, it's practiced just as it sounds. The feet stay together and the kick starts at the upper torso, moving down the body like a wave. If speed is needed, it's always a good one. (It's more difficult in full gear, but manageable)

Our last kick is the frog kick. This one is my favorite. It's very, very efficient, and you can slightly vary it to keep from getting fatigued. The kick itself it a matter of spreading the feet apart and bringing them back together. Despite the name, you don't push with your feet, but keep your legs extended. When the legs are spread, the fins are parallel to the direction of movement, but when you bring them together, the feet are turned towards the perpendicular. As your legs come together, you're thrust forward in a nice smooth motion. This kick is flexible. You can make slight adjustments so you don't wear a particular muscle group out. You can turn the fins on the opposite stroke. Flaring on the spread and parallel on the press.

Once we've covered all the kicks, we let them swim a few laps with whatever kick they want. We keep an eye on them and help smooth out any kinks. People who've never used fins before come up with some uh, interesting ways to use their fins.

Next we move on to donning the skin diving gear under water. We place the mask/snorkel, fins and weight belt on the bottom of the pool. Then we practice donning the weight belt, managing and putting on the fins before they float off, clearing the mask, surfacing and clearing the snorkel. It may seem odd to teach students to do breath hold skills for a SCUBA class, but these all build to harder skills later on.

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SCUBA Theory: Snorkels

Will O'Brien — 2006-08-28T13:11:00+00:00

Filed under: SCUBA Theory

SCUBA Theory is following the wet sessions of a unique, semester(three month) long university level Advanced Open Water SCUBA class. In our first session, we covered mask clearing. You might know just how much I love my snorkel. Today I'll cover the basics of snorkel clearing and we'll even start training for buddy breathing in today's SCUBA Theory.

Gear for today includes the usual weight belt for achieving neutral buoyancy, a mask and a snorkel. As soon as the class is in the water we have them unclip the snorkel and ditch their mask on the side of the pool. This keeps the student isolated to mastering the snorkel. (We'll be taking away our divers masks many times during the class. Snorkel day is a great introduction to this.) One equipment note - we don't teach the students with purge valve equipped snorkels. If they learn clearing with a non-purge snorkel, they'll become far more proficient.

The first skill for the morning is the ever so handy "PTOO-ey" technique. This usually takes the longest to master. The actual clearing is pretty easy, the difficulty is to keep from choking on the residual water. (And not breathing water up your nose without a mask.) The key to not choking is to place your tongue on the roof of your mouth immediately after clearing the snorkel - and before inhaling. When you inhale, any water that would splash into your throat will bounce off your tongue instead of causing the usual choke reflex.

The next clearing technique we cover is displacement. (Which probably won't work very well with most purge valves.) To idea is to clear the snorkel before surfacing. By tilting the head back so the snorkel is five degrees past the horizontal plane, we can clear the snorkel much like a mask. Just before breaking the surface, the diver exhales lightly into the snorkel until the resistance drops. Once the water is out, the diver just looks down so that the snorkel flips out of the water. When done properly, the diver can immediately breath as soon as they surface. This trick takes a minimum of air - but may not be the best in rougher waters.

The next skill of the day is popcorn breathing. I described it thoroughly before, so I'll avoid the details. In a nutshell, we teach them how to breath through a snorkel that's partially filled with water. It's a great skill/proof of the reason for putting the tongue to the roof of the mouth correct. It's an important skill to have, especially if you ever end up breathing on a wet, leaky regulator or are simply snorkeling in rough waters.

Next we bring the skills together by introducing buddy breathing with a snorkel. (I've covered buddy breathing in Sharing Air if you want an overview) The important points of the skill: Maintain control of your air when donating, bubble in between breaths and switch off every two breaths. We do a short review of the hand signals: Low on Air, Out of Air, Need to buddy breath. (If they seem excessive, consider that they are a good device to maintain the focus of a panicking diver.) Teaching all three signals is also beneficial - if you need air from someone who doesn't know your signals, they'll probably figure out what you need.

Before wrapping up class, everyone re-attaches their snorkel to the mask. Now we have them recover the mask, clear it, surface and clear the snorkel. The final task of the morning is to attempt swimming one length underwater. After that, they can practice mask/snorkel recovery in the deep end until it's time to go.

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SCUBA Theory: Get neutral and mask clearing

Will O'Brien — 2006-08-23T16:24:00+00:00

Filed under: SCUBA Theory

School's starting up, and so is the Advanced Open Water class that I work with. This semester, I'm going to follow the wet sessions with my SCUBA Theory entries. The class goes far beyond what a regular dive shop can offer so even if you're certifed, you might want to check it out. Today in SCUBA Theory: neutral weighting and mask clearing

This morning was our first one hour pool session. Everyone is issued a mask and we send them into the pool. The first task is to get the students neutrally buoyant. We usually start everyone out with around ten pounds of weight and start adjusting it. Here's how we do it.

Wearing the weight belt and mask, take a full breath and raise your hands over your head.
Lean over into the water and let yourself sink to the bottom.
Count the number of seconds until you're on the bottom of the pool.
Our goal is between five and eight seconds or so.
Adjust weight and repeat until the timing is right.

Once everyone is weighted properly, we record the weights and move on to clearing the mask. Mask clearing is a basic, but essential skill. Watching new students practice this is a great reminder of just how patient and encouraging we have to be. In order to explain mask clearing, it helps to equate it to pouring water out of a pitcher. In this case, we're pouring air into the mask to displace the water inside. Here's my short introduction to vertical mask clearing.

To keep the mask sealed up top, place your index fingers across the top of the mask skirt.
It may help to tilt the bottom of the mask away from your face slightly.
Slowly exhale air out of your nose into the mask to displace the water.

More often than not, new students try to blast the air out of the mask as fast as they can. To tame these tendencies, I usually tell them to hum the air out of their nose. Humming is a great way to get a feel for how effectively you can clear a mask with a minimum amount of air. Once they've got a feel for it, we have them do it one handed.
When you're not trying to blast the mask off your face, you can simply press against the top of the mask and clear it.

As they get better and better, we add more and more challenges to the skill. They begin with the mask on their head. Then we have them put the mask on and clear it. Next they toss the mask into the water, then retrieve and clear it. Then we move to horizontal mask clearing...

Horizontal clearing is just harder to do. It's less effective, but it comes in handy. As you lay on the pool floor in the horizontal position, turn your head to the side. Hold the mask and exhale. I find it's easier to start facing down and exhale as I turn my head. This usually won't completely clear the mask, but it will get your face clear. With practice, it is possible to get nearly all the water out.

Now that everyone has a handle on mask clearing we take them down to the deep end. Once there, we review equalizing the pressure in the ears. Once they're comfortable with visiting the bottom of the pool, we give them their final challenge of the day. We have them toss their mask into the deep end.
Their last task is to swim to the bottom, put the mask on, clear it and surface.

This last one is where I usually find out who's going to do really well in the class. Most of the students might give it a try, but they'll hang out in the shallow water and balk a bit. The few who keep trying usually end up making the most progress in the class. These guys are the ones who really want to succeed.

At the end of class, we have everyone swim a length for us. Since they'll be swimming some distances later on, a few minutes of helping them improve their stroke goes a long way.

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SCUBA Theory: Popcorn Breathing

Will O'Brien — 2006-05-24T15:34:00+00:00

Filed under: SCUBA Theory

Have you ever been choked a bit by some stray water in your snorkel or a leaky regulator? Today I'm back with another trick to keep you more comfortable in and under the water. You can practice this one in the bath tub, shower, pool, whatever. Check out today's SCUBA Theory!
Popcorn breathing refers to the skill of breathing through water. Here's how to do it.

Partially fill your snorkel with water. (non-ocean is preferred to start out).
Look downward, but don't submerge.
Put the snorkel in your mouth
place your tongue against the roof of your mouth
Slowly breath in. Air will bubble through the water making a sort of popcorn sound.
Congratulations, you can breath through water.

As the air bubbles through it will splash water up into your mouth a bit. Your tongue will keep the water from hitting the back of your throat. Once you get used to doing this, you'll find that you can handle having water in your air supply much easier.

Once you've mastered popcorn breathing, you'll find yourself even more comfortable in the water. Often times if you start to choke on water, placing your tongue on the roof of your mouth can help regain calm and suppress your gagging reflex. If you're having a rough time clearing a snorkel, this allows you to grab some more air and finish clearing the rest of the water.

Every student I've helped has managed this skill. If it's difficult the first few times you try it, take a little water out of the snorkel and try again. Once you mastered it, try adding some more water or doing it with your head submerged. Stack the odds against you and leave your mask off.

The more you can challenge yourself in controlled conditions, the more relaxed you'll be during your dives.
If you're relaxed, you'll have more fun. Oh, when you're done with this one, go do some locomotives.

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SCUBA Theory: Holding your breath is a skill

Will O'Brien — 2006-04-17T08:17:00+00:00

Filed under: SCUBA Theory

"Don't hold your breath" is a mantra heard in virtually every scuba diving course every taught. You can easily damage your body during ascention by holding your breath during SCUBA diving. The expansion of the air can quickly cause damage regions with very few nerve endings to tell you that you're doing bad things to yourself. Today in SCUBA Theory, why breath holding is a valuable skill to practice.

That's not my weight belt

Hear me out before you start thinking about how buoyant I'd be with an extra fifty pounds of lead. The most dangerous thing a diver can experience under the water is panic. If you stick the average person under water, in about thirty seconds they're going to be getting worried about their next breath of air. Especially if they've been swimming. The truth is that the average person can be fully functional under water for a couple of minutes without any fresh air.

Feel the burn

Our brain tells us to exhale when the carbon dioxide level in our lungs reaches a certain threshold. After thirty seconds have passed, we really want to start breathing again because that threshold has been met, and likely surpassed. Keep at it long enough, and you'll really start to feel uncomfortable. The important consideration is that we decide to breath based on CO2 buildup rather than the lack of oxygen in our lungs.

Eternityschmernity

Thirty seconds is a relatively short period of time. If you experience an out of air situation, it'll will feel like an eternity. It's very likely to take you at least thirty seconds to determine if you need to get air from your buddy, to swim over to him in full gear, signal that you need air and receive assistance. In that situation, staying calm keeps you from making mistakes. Being comfortable under the water is important, especially when a diver is under duress.

Get skinny

Practicing skin diving skills that involve breath holding in the pool is a great way to increase your water comfort and confidence. You should NEVER hold your breath while scuba diving, but practicing it while skin diving is can help you become a better SCUBA diver. Increased water comfort means increased ability to handle duress under the water.

Go jump in a ... pool

I keep a set of skin diving gear - mask, snorkel, fins and weight belt just for pool work. This keeps the chlorine off my good diving gear and I just keep them ready to use in the back of my car.

Test yourself

Place your fins on the bottom of the pool and stick your weight belt on top of them. Now leave your mask next to them. On one breath of air, descend, put on your gear, clear your mask, and ascend. This little task can take a while. You'll float upward until you put on your belt, and when you pick it up your fins may try to escape. Try it in the shallow end first, but once you've got it down head to the deep end of the pool.

You loco?

If you're hurting to pull off the task above, my favorite workout designed to help is called the locomotive. Wearing a mask, fins and snorkel (hopefully a suit too) swim laps. Halfway down the lane, descend a bit and swim as much of the rest of the length underwater as you can. When you ascend, clear your snorkel and keep going. Using your arms to increase your oxygen burn can really increase the effectiveness. The locomotives will push you to deal with your CO2 tolerance threshold. Doing four to eight locomotive laps during three or four pool sessions will start to make a difference.

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SCUBA Theory: Rebreather 101

Will O'Brien — 2006-03-30T13:04:00+00:00

Filed under: SCUBA Theory

Sport divers are instructed on the use of open circuit SCUBA. Rebreathers are a bit of an enigma. Commercial units are expensive, complicated and get pretty weird looks on the diving boat. Surprisingly, rebreathers have been around for longer than modern open circuit SCUBA diving. Today in SCUBA Theory, we're covering basic rebreather theory.

How it works

During respiration, oxygen is absorbed and carbon dioxide is expelled. Atmospheric air is only about 21 percent oxygen. The rest of the gasses are inert and simply pass in and out of the lungs. (The body can and does absorb inert gasses, it just doesn't metabolize them) In open circuit SCUBA diving, used air is exhausted into the water.

In a closed rebreather system, the carbon dioxide is removed from the expelled air, and oxygen is reintroduced in it's place. The inert gasses are recycled.
The fundamental operation of a rebreather is really very simple. The complications come in the form of construction and use.

Oxywhat?

The amount of oxygen in the circulating air must be kept at a safe level. Too much means oxygen toxicity, too little means hypoxia. Both conditions are difficult to safely manage underwater. Remember Boyle's Law? As pressure increases, the volume of a gas decreases. As someone diving a rebreather ascends and descends, the inert gas volume and partial pressure of oxygen both need to be adjusted accordingly. Just clearing a mask now has new implications on the divers air management. To take a rebreather system to any real depth (over 20 feet) the system needs an additional source of inert gas.

Micro-management is good

Modern rebreathers cost thousands of dollars. Oxygen levels are constantly monitored with electronic sensors. These systems certainly well designed, but require quite a bit of knowledge and training to safely use them. The safety of using a rebreather is greatly increased once the diver can monitor the amount of oxygen in the system. However, if your SCUBA diving computer fails, you've only lost your diving history. If the electronics on a modern rebreather experiences failure, serious situations could result. (Of course, they have manual controls and spare gauges for backup) But because the system must be very robust, the cost of the system increased dramatically. Today, a low-end rebreather costs about as much as a full set of some of the best SCUBA gear you can buy.

Cheaters!

OK. It's not really cheating, but there are advantages to using rebreathers. By controlling the amount of inert gas and the amount of oxygen in the system, the rebreather now has deeper operating depths. Thanks to the closed system, they can dive longer with much smaller tanks. With the use of an inert gas that doesn't become an anesthetic at depth, nitrogen narcosis is taken out of the equation. With control of the gas mixture there is now the possibility of reducing decompression times.

Oh, and don't forget that the guy diving the rebreather isn't releasing a torrent of bubbles to scare away the fish. The lack of bubbles seems to be the favorite reason for diving rebreathers.

Limits

Lots of people are curious about depth limits of rebreathers. The rated depth for each device is completely dependent on it's design. People on the bleeding edge (people tend to die trying this) are saying near 200 meters of depth is possible.

If you're really interested in the various types of rebreathers, there's a short writeup explaining the differences between oxygen only, closed and semi-closed circuit rebreathers. Bill Reals recommends Mastering Rebreathers for further reading. If you're looking for more information online, check out A Learners Guide To Closed-Circuit Rebreather Operations by Richard Pyle at Rebreather World.

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SCUBA Theory: Sharing air

Will O'Brien — 2006-03-20T07:16:00+00:00

Filed under: SCUBA Theory

How do you donate air? There's more than one way to do it. That random dive buddy you ended up with at the boat dock might do something unexpected in an out of air situation. SCUBA Theory is back again. Today, it's all about sharing air.

How do you share?

Divers naturally share air the way they were trained to. Training methods vary between shops, instructors and organizations. Being caught off guard because someone had different training can have serious consequences. Even if you only dive with specifically trained buddies, you may be called upon to assist or even rely upon someone else who isn't.

You gave them what?

When a (sport) diver donates air, he usually has three options:
1. Donate primary regulator, and switch to the backup or octopus regulator.
2. Donate backup regulator and keep the primary regulator.
3. Buddy breathe. This involves sharing a single regulator between two divers.

It also juliennes

One dive shop teaches their open water students to donate their backup or octo regulators. At another shop, all the BCs are equipped with SCUBAPRO Air2 power inflater/regulator hybrids. So, they teach their students to donate their primary regulator. At another, the instructor teaches buddy breathing. To prevent confusing students, and due to the short amount of water time in most open water courses, it seems very few will cover more than one air donation technique.

The danger of the octo

Having a backup regulator is a great concept. The problem comes when a diver puts a backup regulator in his mouth and finds that it's full of sand.

If the regulator becomes fouled such that the diaphragm or purge valve can't operate, then it is useless. Donating a fouled octo regulator to an air-starved diver is even worse. They exhale to clear the regulator of water and hastily suck in only to receive a mouthful of sand or muck. If they're expecting air and end up choking on this stuff... well the Heimlich maneuver is a bit hard underwater with a tank on your victims back. (And wouldn't help much with sand, anyway.) A far better plan is to donate your primary regulator. You'll have plenty of time to determine if your backup is fully operational and to take appropriate action.

If you're the diver who is out of air, be careful if someone hands you their octo. Hitting the purge button before you ever put it in your mouth is probably a good idea. Keep in mind that the regulator could be fouled, so be mentally prepared to have to wait a little longer for that breath of life.

'Don't Panic'

If a diver is hurting for air, they might start to panic. They'll want the first regulator that they see and know has air: the one in your mouth. It's a good idea to stay in control of your regulator. If a diver looks like they may need air, place your hand on your regulator. It's better for you to hand it to them than have it yanked out of your mouth. You can make sure you grab a nice breath of air and demonstrate that you're calm while handing it over. Someone who's been swimming without an air supply will usually feel the need to catch their breath. If you just exhaled and a panicked diver grabs your regulator, you may not be very happy while they're gobbling up air.

Buddy breathing with Dave and Bob

Even if you never need it, buddy breathing is a great skill to have under the weight belt. Practicing it can really help increase a divers comfort level with regulator swapping.

Bob signals he's low on air, out of air and needs to share air/buddy breath. Dave puts his hand on his regulator and grabs a breath of air. Bob places his hand over Dave's or on the hose right next to the regulator. Dave and Bob should grab each others BC, strap or arms to maintain a steady distance. Dave will place the regulator at Bob's mouth and Bob will get two even breaths on the regulator. Dave and Bob will then put the regulator at Dave's mouth where he'll get two breaths. They continue to share. While the regulator is out of either diver's mouth, he'll continuously bubble air to prevent baro-trauma.

Since Dave put his hand on the regulator first, he can keep control over his air supply. This makes it easier for Dave to retrieve his regulator if Bob starts panicking and tries to keep the regulator to himself. If Bob really panics and tries to shoot for the surface, Dave a better chance of pulling his regulator away if he's being pulled upward at an unsafe ascent speed.

What works for me

I'm going to stay away from discussing long or short regulator hoses for now. I do have to give credit to the tech divers for my preferred method of backup regulator storage. 'DIR' technical divers keep their secondary regulator on a bungee or latex hose necklace. (The ends of the bungee/hose are zip tied at the mouth piece mount of the regulator.) It sounds a little weird, but it's very good in practice. The backup regulator sits under their chin, so when it's needed it's probably clear of debris. It's also very, very easy to reach without looking and place the backup regulator in your mouth.

I'll donate my known working primary regulator to the air starved diver. At the same time I clear and if it's functioning, start breathing off my backup regulator. Once I know it's operational (and I don't need to retrieve my primary to breath) and the diver in need is calm, signals ok, and is ready to ascend I have the option of letting them keep the primary. In the case that my secondary regulator has failed me in some way, I've maintained control so I can buddy breath with the diver in need and still ascend safely.

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SCUBA Theory: Snorkels aren't evil

Will O'Brien — 2006-03-14T16:42:00+00:00

Filed under: SCUBA Theory

We're beginning a series on SCUBA diving theory. Not only will we explore techniques and best practices in safety, we'll talk about the reasons behind them. Bad puns will abound as we dive into everything from using and maintaining your gear to compartmental decompression theory. Today, snorkels: they aren't evil.

Do you carry a snorkel on your dives?

I've met several divers lately who leave the snorkel at home when they go SCUBA diving. The snorkel has become percieved as dead weight that tugs at the mask strap. Today I'll talk about the importance of strapping that tube to your head.

Snorkels are annoying

They add extra drag to your head. They poke you in the chin. You forgot the one that isn't pink...
Yup, they're just obnoxious, until you need them.

I'm diving, not snorkeling

According to reports by DAN(The Divers Alert Network), the majority of diving deaths at the surface in 2005 were due to exhaustion. In one case a diver drowned at the surface after he dropped his regulator because his tank was empty at the beginning of his dive.

That boy's head is like Sputnik

In full diving kit, keeping your head above water is very exhausting. The human head averages about 12 pounds. That's a big weight to keep out of the water. Oh, and don't forget that the top of the tank and your regulator are poking out of the water. Lets make that 20 to 25 pounds of dead weight. Inflating your BC will offset the weight of your noggin, but todays BCs are not designed to keep the divers head out of water.

Please sir, make them smaller

It's not entirely the diver's fault that snorkels are being left behind. It has become difficult to find a simple, streamlined snorkel in a dive shop. Purge valves certainly make clearing a snorkel very easy. Unfortunately adding a purge valve makes the snorkel bigger and heavier, resulting in more drag on the divers head. My favorite, trusty, valve free SCUBAPRO snorkel isn't even made anymore. Purge valves are simple devices, but they can fail. A piece of sand in the right place can turn that spiffy valve into a water inlet. Aside from children's gear, my local dive shop doesn't even carry a snorkel without a purge valve.

You're still not convinced?

For the local Advanced Open Water course, we have a skill designed to prove the importance of the snorkel. In full gear, the divers swim laps around the pool with everything but a snorkel. In a class filled with 20 year olds in good physical condition, most hit exhaustion between 5 and 8 laps or 250 to 400 yards! After a break, we give them back their snorkel. Once their heads is comfortably in the water, previously exhausted students easily swim the same distance and more with very little energy use. This skill is designed to produce exhaustion, DO NOT try it without an instructor to keep you safe.

Failure is not an option

Have you really considered what happens if you experience an equipment failure at the surface? An aborted dive can easily result in surfacing away from the dive boat. BC failure, broken fin straps, an un-recoverable free flowing regulator all become more serious problems if you left your snorkel in your bag. Even in an out of air situation, most people take their regulators back once they get you to the surface.

Gearing up?

Every year, several diving deaths occur at the water surface. The majority of these deaths are due to exhaustion. Snorkels may be a drag, but carrying your head out of the water is even worse. Swimming at the surface in full gear without a snorkel will quickly exhaust even the most physically fit diver. The snorkel is sort of a secret seat belt for divers at the surface.

Me? I carry my snorkel on every dive.
I'll even take the pink one.

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