3/20/2011 - Muffler

A muffler is a device for reducing the amount of noise emitted by the exhaust of an internal combustion engine. The muffler reduces exhaust noise by absorption – the exhaust is routed through a series of passages and chambers lined with roving fiberglass wool – and/or resonating chambers tuned to cause destructive interference wherein opposite sound waves cancel each other out. Changing the muffler can change the sound of a car's exhaust system considerably. Removing a vehicle's muffler or installing a less effective muffler than the original can cause the vehicle to violate noise regulations. Nevertheless some vehicle owners remove their car muffler in the belief it will improve performance, or just to make them louder.

Indeed, we never appreciate what we have. For all the years I lived in NYC and Saint-Petersburg I constantly complained about the traffic noise. Little did I know! The traffic noise of NYC is nothing compared to the unmuffled (or maybe demuffled) horror of this little Mexican paradise. None of the islanders seems to have heard about the muffler. I can kind of understand (though not condone) how some macho men would want to have no muffler on their motorcycles, but family men! girls! respectable looking ladies! Honestly!!!

I've been trying to figure out how I can make a difference here, for my own sake and for all of us who appreciate silence. If you have any ideas on how to launch an effective muffler campaign on this island, DO share!

March 17th – The birds

On the road along the ocean, there are a lot of trees starting at La Mega* and going south. But this one little oasis of 10-12 trees between La Mega and Chedraui* is very odd. Every time I pass by those particular trees on my bicycle, I get startled by the loudest bird chatter I have ever heard in my life. Well, maybe I'm exaggerating a bit – in Brazil birds are pretty loud as well. But here it's just so sudden. I like riding my bike over there either early in the morning or late at night when the street is almost deserted. This is the only time I can ride along the ocean enjoying the quiet (at all other hours of the day traffic noise is unbelievable). It is so beautiful to ride and ride and ride, without thinking anything, without rushing anywhere, just enjoying the beauty of the sea… And all of a sudden – MJEH- MJEH- MJEH- MJEH- MJEH- MJEH- MJEH- MJEH- MJEH (hmmm, it took me a while to come up with a transcription for the impossibly loud bird chatter, is there a correct way of doing it I wonder?). This goes on along those ten trees on the road and all of a sudden – complete silence again. Weird.

*Two big supermarkets in Cozumel

March 14th – Doubts

I had a complete break-down today. I feel really bad for Javier who had to deal with my sobbing hysteria right after we returned home from our dive trip. "Oh no! I'm just not made up for this! Why do I keep pushing myself if every single thing about diving takes me forever to master??? Yes, I'm good now, but what effort has this cost me, how much time!" – I kept waling on an on. Javier's mere presence is always soothing though, underwater and at the surface, and fortunately for everybody after a little while I finally calmed down. So now I can actually describe what pushed me off the rocker.

This morning I connected a new long hose to my regulator, for the octopus used for the purposes of comfortable air-sharing in order to extend a dive's bottom time. I wasn't really sure how to efficiently "store" it on my BCD though, so I just went the cave-style way and wrapped it around my neck. Apparently, I hadn't done it skillfully enough, because when the necessity of sharing air presented itself, I realized that the octopus is absolutely impossible to get to without me taking my primary out of my mouth and making a thousand other ridiculous moves. Which I started doing – no big deal. Well, in diving there's no such thing as "no big deal". Every tiny problem has a winning chance of becoming a huge issue. And so it snowballed on me. The client was kind of impatient or maybe he was just trying to be helpful, and he grabbed the octopus from my hand before I was able to completely detangle the whole thing. That put me on the wrong side of him. The crazy current made it difficult to quickly switch sides. In the process the guy must have pressed the inflator button on his BCD by accident and since I was in the process of moving sides, I wasn't close enough to react immediately by hitting the deflator button. The guy was much bigger than I am. He was pulling me up. I tried to stay down, grab his leg and at the same time communicate to him the proper actions. He was completely unresponsive. We kept going up. My computer was beeping annoyingly, announcing that I'm going up too fast. Needless to say, I hate this sound: I'm very paranoid about the decompression sickness, air embolism and other lung overexpansion injuries, and usually follow my very conservative computer without any further questioning (for example, I have never even gone into the decompression mode once in my life). I thought to myself, "Screw him, why should I go up to the surface with him? He is a certified diver, let him do whatever the hell he wants, but I'm not bubbling up here!" and I started to swim down, trying to pull him with me. Well, he was too heavy for me, and all I managed to do was yank the octopus out of his mouth and stay down, while the guy shot up to the surface. Luckily for my consciousness, he had anticipated the separation and immediately stuck his own regulator into his mouth. So nothing bad really happened. But this incident completely shook me.

Of course, in the end of the day, I did everything right – my safety is the priority. But… If I hadn't entangled the octopus to begin with, or if I hadn't let him grab it before I was ready to share air, or if I had paid enough attention to his inflator, or if I had been quick enough to reach for his deflator button, or – well, I don't even know, probably a thousand more "or" solutions can be added here, the bottom line is "if I hadn't" something, the whole situation could have been easily avoided. I have the only frustrating thing in my life right now, and it's the fact that I find myself absolutely incapable of reconciling with the idea that "I'm good, but I'm not that good". I have never been "not that good" in anything I do. I immediately become "the best" (well, relatively speaking, let's be at least somewhat modest). It's such an alien sensation for me to not be able to quickly "get" everything, to succeed at the very first attempt. Theoretically, I know everything I could have and probably should have done in this situation, but I was just physically unable to apply this knowledge to practice. Why? Why, why, why my body refuses to be quick, damn it!? Argh!!! I'm so mad at my parents today for not pushing me to do sports when I was a child. How could they do this to me? Now every time I need to learn a new physical skill, it looks like I have to first suffer through the humiliation of sucking at it tremendously before the mastery finally comes. This is just not cool. But I cannot live without diving anymore, so I know that I'll just keep sucking until I don't suck. I guess, it's necessary to expand your comfort zone from time to time…

March 11th – A perfect Sunday

Today is Friday, but it feels like a Sunday. In fact, it feels like a perfect New York Sunday. Because of yet another Norte today, nobody is working. David came over early in the morning, to chat and hang out. And this is when our "Sunday" began. We went to brunch at the Camaron Dorado, a great place for breakfast tacos and tortas (sandwiches). Nobody was in a hurry and we just sat there forever, chatting and laughing.

Sleepy with food and sun, I stayed in the hammock for a couple of hours. Hammocks always entrance me, and instead of reading the book I took with me, I just stared at the sky.

Then we all went to the movies. We wanted to see this movie Sanctum about cave diving, but of course with our luck last day of this one was yesterday. We went anyway and saw Karma. Both De Niro and Ed Norton were spectacular, but the movie itself is really nothing to write home about. A slice of life, and not a very happy life.

And as if this wasn't enough to call it a nice day, Javier and I went to the museum for a piano concert. It was unexpectedly good. Two girls – one from Bulgaria, the other from Hungary – were playing Mozart, Schubert, Brahms, four hands. The audience was full. Some people were even sitting on the steps or standing. And it was mostly locals, just a few tourists. The concert was free, too! It was really a great treat.

On the way back home, in the breezy darkness of the night, we were silent, digesting the fullness of the day. I never thought Cozumel can offer a New York Sunday feel. I totally underestimated this island. Well, now I know better…

March 7th – March 10th – The business of transformation

This week I get to practice my dive master skills while diving with Liang at Aldora. I come to the pier half an hour earlier than clients, load the boat, assemble their gear, meet and greet them, help them underwater if need be, throw the line at the pier (this is the most difficult part!). I even guided a couple of dives.

I cannot thank Liang enough for letting me have my first guiding experience at my favorite dive site – San Juan. Although Liang was in the water with me, I did all the guiding entirely by myself. I told the group it was my first guide, and I think they got a little scared, so everybody stayed close and behavedJ. Good! I went in the front and even in the usual San Juan current was able to find some cool stuff: turtles, crabs, and a green moray eel. When I was taking my dive master course, my two concerns about my future guiding were (1) that I'd get lost and (2) that I'd be super nervous. I'm very much surprised that I didn't get nervous at all. This instructor course truly gave me a lot of calm confidence. I'm no less surprised that I didn't get lost! Actually, it was easier than I had imagined – I guess, if the current goes the right way, there's really no reason to worry about getting lost, you just go along the reef. It was so exciting! I also guided the night dive at Villa Blanca on the same day. And that went very well too. Although this time I was completely in the dark. Literally and figuratively – I had absolutely no clue where I was. But apparently it doesn't really matter, as long as you are on the reef, sometimes making little detours to the sandy bottom to find an octopus or two. On the night dive it's even easier to make sure everybody is where they are supposed to be – you can see the lights much better than the bubbles during the day. All in all my first time was spectacular! I wonder how it will feel though when I'm all by myself, without the reassuring presence of Liang in the back of the group…

Dive stories

This week we are diving with a group of friends from Florida. Three guys and a girl. They are all barely 25 years old, super fit (although all of them smoke) and super energetic. One of them has some MS-like condition and from time to time gets fits of not being able to control his muscles underwater. In moments like this he has to hang on to something with both hands and just wait several seconds until it passes. He dives fairly well though and what's even more important he is constantly actively working on improving his skills (unfortunately, not a very common quality among certified divers). On the second dive this Monday though he got completely distressed all of a sudden by the reading of his SPG – 700 psi, but it was at the very end of the dive, and Liang already signaled everybody to start coming up for a safety stop. I was next to him at the end of the group and witnessed his panic grow. His eyes were wide open and he constantly turned to me to make sure I understand that he had "only" 700 psi. No matter how many times I signaled "OK" to him and tried to point out that we were already coming up, he was not really responsive. So I decided to take action, as learned from the rescue course exercise "Distressed out-of-air diver". I shared air with him and brought him up to the safety stop. It was a bit difficult though. He is very heavy underwater, plus when he gets to one of his fits he freezes and becomes even heavier and because of my BCD configuration I had to share my primary air source with him and breathe out of the second stage on my low pressure hose, so it took me some effort to adjust our buoyancy to go up slowly, as I had to take the second stage out of my mouth every time I needed to put or release some air from the BCD. It was all good in the end though. Again, very impressed with my not being nervous at all. And it will never stop to amaze me that people with disabilities possess so much internal strength to not give up on a "normal" active life. In fact, I think they sometimes live a much fuller life than the healthier of us…

On Tuesday, we went to Devil's Throat. It's a deep dive. You come out of the "throat" at about 110 feet and then slowly start coming up. I was at the rear of the group again and witnessed a funny scene. One of the divers (not from the above-mentioned group) swam out of the Devil's Throat right up to another diver and undid the strap on his tank. Naturally, the tank started slipping out. I was right there, so I was able to quickly put it back and tighten it again. But what the hell? It couldn't have been a joke, they are not friends or anything. Was the guy narked only at 110 feet? Strange.

On Wednesday, Laura – the girl from the young friends group – asked me for my email address. She said that they had been talking about quitting their jobs for a while and moving somewhere warm, but it had always been just a talk. Apparently, my "story" inspired them to make their dream a reality. They just want to stay in touch with me in case they have some questions. Wow, I'm honored to be a muse for such an exciting and liberating life decision!

In the PADI instructor course they teach you that as a dive professional you join the "business of transformation". It sounds cheesy. But isn't it so true?

February 20th – March 6th: The IDC bootcamp

I'm not sure I remember how to write anymore. But I sure as hell remember that the student-to-instructor ratio is 8:1 for the Advanced Open Water course and 6:1 for Bubblemaker, that recreational dive tables use a 14 tissue compartment model with the 60-minute compartment controlling the dive, and that at altitude a capillary gauge will convert actual depths to theoretical.

IDC stands for Instructor Development Course, but I think they should seriously consider renaming it into IDB, "B" for "bootcamp". I have not studied that hard since my first year in the University 20 years ago (wow, 20 years…)! For 2 weeks straight we had classes from 9AM till 6PM, plus homework. And there's a lot of physical activity, of course, which I'm not really used to. I couldn't even read a book before bed, the second my head touched the pillow, I was completely gone.

I was reluctant to go straight to the instructorship so soon after completing the Dive Master course, but Liang and Javier insisted that it was the right thing to do, "while everything is fresh in your mind". The first couple of days were emotionally (and physically) awful. I kept making a ton of mistakes, which made me doubt the path I'd chosen even more. As days went by though I realized that I was getting more and more sure of my abilities, my confidence was building up as I gained more and more knowledge, and by the end of the course I was actually eager to start teaching as soon as possible. This is really amazing: in two weeks I went from the abyss of self-doubt to the peak of self-confidence. I wish all the courses were designed this way. Yes, it's very intense and demanding physically and intellectually (as well as financially), but it's so worth it! (I'm going to make a good sales person for PADIJ).

The water classes in this course are structured around skills from different levels of diving education. You are assigned a few skills every day to present before the class. The presentation consists of a briefing, an underwater part, and a debriefing after the dive. During the underwater part you have to demonstrate the skill first in a certain way – slow, exaggerated, making it look easy – and then invite "students" (your fellow instructor candidates play the part) to perform the same skill. The "students" are asked to make different mistakes and you are supposed to catch them. Mistakes are of two kinds: the ones that are essential to the skill but not necessarily detrimental to the safety, and the ones that can potentially kill your student. If you don't catch the latter you fail the assignment. I failed several times. To be fair though, everybody failed at least a couple of times as well. PADI (Professional Association of Dive Instructors) is very particular about the way you perform everything, classroom or underwater. There are certain things that you must mention in your briefing and debriefing, otherwise points are taken off your total score. For example, in the briefing you have to make sure to clearly state the objective and the value of the skill, the steps to perform it and the signals that will be used while performing it. In the debriefing the most important part is positive reinforcement. Even if the students sucked every step of the way, you must find something that they did well and mention it to pump up their confidence. The second you pop your head out of the water after the dive, you have to shout enthusiastically, "Wow, you guys did so well! I'm so impressed with the way you breathed (or moved your fins, or looked sharp, or whatever)!" I mastered that partJ. All my fellow instructor candidates were looking forward to my positive reinforcement speeches, as I would always come up with something ridiculous to point out with the greatest zest. I have always been good at positive reinforcement. Perhaps because this is the only style that works on me. (If you want to see an IDC skill demonstration in action, click here. And this one is the funniest rescue exercise performance ever!)

The classroom sessions are very similar. Nowadays everybody learns diving theory for each level from printed manuals or eLearning, there are no real lectures anymore. The only time you provide explanations is when students make mistakes on quizzes and/or exams. Then, you have to go over the questions that they get wrong, explaining in detail how things work. Again, the PADI way is very particular. For each classroom presentation you have to follow a certain protocol. There are 3 parts to this: introduction – when you tell your students what you are going to tell them in a second; body – when you actually tell your students what's up; and summary – when you tell them what you have just told them. In each part you have to talk about specific things and make sure you promote local diving and PADI continuing education and try to sell some piece of equipment (PADI also stands for "Put Another Dollar In"). Again, if you forget anything, you get points taken off your total score. For example, here's the way you would present an explanation of the following question from the Dive Master course, "How does the physiological effect of breathing a given percentage of gas at depth compare to breathing the same percentage of the gas at the surface?"

INTRODUCTION

Contact / Value: Have you by any chance climbed Mount Kilimanjaro? Even if you haven't, you probably know that it is a serious, several day endeavor. You have to stop at some plateaus as you climb up to adjust for the higher altitude. Why is that, you think? Actually, because the higher you get the lower the atmospheric pressure becomes, and this results in lower levels of oxygen in the air you breathe in. It is important to understand the effect of the atmospheric pressure on gas components because this allows you to take appropriate safety measures. (Tell the story of Dana and her husband climbing Mount Kilimanjaro for their honeymoon: she had to leave him on one of the platforms because he was altitude sick).

Reinforce value with a diving application: The same concept applies to diving, but in this case the pressure increases as we go down, so the level of each gas comprising air becomes higher and higher as you go deeper. It is very important to understand this relationship, again, for the safety reasons, because both nitrogen narcosis and oxygen toxicity are results of higher gas level in the mixture you breathe in while diving.

Conduct: Please open your Encyclopedia of Recreational Diving to page 4-31.

BODY

Objective: Our objective is to answer this question – How does the physiological effect of breathing a given percentage of gas at depth compare to breathing the same percentage of the gas at the surface?

Key Points: Let's look at this lesson guide (Instructor Manual 2009 – Page 99).

1. The body responds to a gas you breathe based on its partial pressure and NOT the percentage of the gas in the mix. As the pressure increases, the physiological effect increases.
   
2. As the pressure increases with depth, you breathe more and more molecules of each gas in the mixture in your tank.
   
3. For example, if you breathe air at 40m/130f, the PO2 is (0.21 x 5ata = 1.05ata), which is approximately the same as breathing 100% oxygen at the surface with PO2 = .1 x 1ata = 1 ata.
   
4. The increased PN2 causes nitrogen narcosis.
   
5. The increased PO2 causes oxygen toxicity (a concern with diving on nitrox).
   
6. Contaminated air in your tank that may barely cause any problems at the surface may lead to a fatality while breathed in underwater at some serious depth.
   

Example(s) of actual circumstances: The other day we had this incident at Aldora when the diver went straight to 213 feet from Devil's Throat. Without a doubt, he was seeking the physiological effect of increased partial pressure of nitrogen – nitrogen narcosis.

Application to local environment: Devil's Throat

Relation to other components of this course: Remember, we talked about nitrogen narcosis a couple of days ago while discussing the physiology of diving?

Related dive equipment to promote: SHOW IT BOTH TIMES (here and in the summary) So depth is a very important consideration for partial pressure calculations. Please make sure you frequently check your computers and if you dive on nitrox, make sure you set your computers to the correct O2 maximum partial pressure (1.4-1.6).

Example(s) from PADI Continuing Education courses: If you are interested in learning more about the subject, there are very valuable PADI courses that you can check out - Nitrox and Advanced Nitrox.

Do you have any questions?

SUMMARY

Reinforce value with application: To summarize, it is important to understand the physiological effect of partial pressure at depth for safety reasons.

Restate objective(s): So how does the physiological effect of breathing a given percentage of gas at depth compare to breathing the same percentage of the gas at the surface?

Review key points:

1. As the pressure increases with depth, you breathe more and more molecules of each gas in the mixture in your tank.
   
2. For example, if you breathe air at 40m/130f, the PO2 is (0.21 x 5ata = 1.05ata), which is approximately the same as breathing 100% oxygen at the surface with PO2 = .1 x 1ata = 1 ata.
   

Promote PADI Continuing Education: Don't forget, you can take Nitrox course at any time. It doesn't even require diving nowadays. Or if you are interested in Advanced Nitrox, please talk to me and I'll arrange it for you with our tech diver instructor.

Promote equipment ownership or dive travel (SHOW IT) : If you are like Catherine and already have Advanced Nitrox certification, I have nothing else to do but try to sell you a computerJ, and perhaps an air analyzer.

The Instructor Exam takes place in Playa del Carmen, right across from Cozumel by ferry. It takes two days and is conducted by an independent PADI examiner (not your coach as they do in all other PADI courses). The first day you do all the theory exams (6 topics – General Standards, Physics, Physiology, Environment, Equipment, Dive Tables), a classroom presentation and all the confined water presentations; and the next day you go to one of the cenotes to perform your open water presentation. We were very nervous about the exams because we were told that our examiner was the toughest ever. Catherine and I (we were the only two candidates from Cozumel) studied like crazy and checked and double-checked each other on everything. Catherine is a New Yorker. 35, born and raised in Brooklyn, she is an interesting character: extrovert, talkative, always on the run, always expressing the need to be busy with new things and new activities (I can tell from my own experience that this too shall passJ). She just quit her job (she managed a small legal firm in Manhattan) a couple of months ago to move here and try on a new life. She found a boyfriend and a job as a dive master with one of the boats here and has been enjoying the new set-up ever since. It's interesting to watch somebody go through the same life plot. She is now at the peak of exaltation about everything new in her life, drunk with her own courage to deviate from the "norm". I, too, was there a year ago. With time the initial agitated excitement in me gave way to the internal peace and quiet. I wonder if it's common to get to this state. I will be watching Catherine through this, I think it's an interesting experiment.

The examiner didn't appear as strict as promised though. He was fair, but not really hung up on every minuscule standard. I think it's good: obviously, during the exam people can make little mistakes just because they are super nervous. Surprisingly, I was not stressed at all. I was right before the exam, but as soon as I entered the water, all of a sudden I was absolutely calm and collected and made no mistakes whatsoever. I was really pleased with my performance. I certainly deserved this certificate:

And I am certainly ready to certify my own students now! How strange life is. It was only two years ago that I reluctantly entered the water for the first time, scared to death to breathe through a regulator, and today I'm eager to teach a complete novice how to do it… Human beings are really amazing creatures.