News from Down Under Dive Shop

Howdy gang,
If you've were in the Gulf this past week then you know what I'm about to say is true.
Viz was awesome!
We had some of the best conditions ever out on the carrier.  100' plus viz.  The YDTs and Petes Tide were equally putting on a show.  How about those big Sandbar Sharks.  Sweet!
This weekend we saw lots of tropicals  and an octopus or two on Nu' Barge.
Navy Tug put on a show with tons of fish and even a  bull shark at the end of the dive.

We topped off the week with a triple dip at Three Mile Barge.  Most of the crew claims to have never witnessed viz like that before on the old barge.
We hosted a Fish Id clinic where the winner, Open Water Student, Lance Olsen won a pair of Polarized Ocean Reef Sunglasses for Identifying the most fish correctly.  He should probably keep it a secret that he is a marine biologist.

First Open Water Dives:
Lance Olsen, Will Johnson, Michael Perkinson, Phillip Garder, Frank Selesky, Luke Caden, Jena Rush, and Bruce Burge.  Yaaaay!

Advanced Open Water: Garret Johnson

PADI Deep Diver:  Jessica Polk

PADI Sidemount Divers: Stephen Wilde and Joe Velie.

How about a round of applause for all of Down Under's newly certified divers.

Diver! Diver! Are you ok?
IDC Staff Instructor and Public Safety Diver Instructor Jim Mahan will be leading the PADI Rescue Diver course October 6th and 7th.  You will practice life saving techniques and develop habits that will transform you from a watcher to a watchdog.  
Read More.

Dive Travel!!!
Bahmas Sail and Dive Adventure October October 20th-26th

Contact Jim @ or call 251-968-3483 (DIVE) to sign up.  Full Payment required upon booking.  Flight not included. 


The Instructor's Corner (NITROX)

Hi Team,
After multiple conversations this week about the same topic (Enriched Air Nitrox Diving) I thought it would be useful to resurrect an old column  that we used to do back in the day of snail mail and actual paper newsletters, The Instructor's Corner.  These brief articles covered general knowledge and our techniques on topics such as local beach diving and how the pros do it, safe and general computer diving, practices, boat diving, spearfishing and so on.  Some of these articles have even been published in the past like Beth's mask clearing made easy in Dive Training Magazine and Bryan's & Hugh's tip's from the pros in PADI's Sport Diver Magazine.

OK, first off I am not a physicist or anything of the like.  Matter of fact I am an artist so numbers and math are all goofy in my head anyway, but if I can learn this stuff anyone can.
If you are not Nitrox Certified then hop over to the e-Learning page and lets get er done.  
To truly understand Enriched Air or Nitrox Diving, you need training! This article is only a quick overview on Oxygen Management and a quick introduction to Enriched Air Diving. Do not attempt, in any way, to use this article or any of the construed advice as training. Do not dive Enriched Air unless you are certified and qualified to do so. That means a certified Enriched Air Scuba Instructor has signed off that you are trained to dive Enriched Air. Scuba diving is a great sport, but dangerous if you do not dive within your training limits.

Nitrox made Easy

If you need a quick review then check out this article.

Here is the skinny,
(As stated above this is not training so all of you tekkies and physics and physiology nerds keep your two cents to yourself, this is a basic discussion for basic use for beginner divers)

What is Nitrox and why is it good?

Enriched Air Nitrox is a mix of breathing gas that contains a higher percentage of Oxygen than normal air. Typically 28% to 40%, but anything higher than 21% can be considered "Nitrox".  The two most common mixes for our area of the Gulf is EAN28 and EAN32.  
The general idea behind Nitrox is that our bottom time is limited by the amount of Nitrogen we take in "on gas" and can "off gas" safely with our limited amount of time/gas.  So by removing some Nitrogen we should be able to stay down longer.  
This science is true with one added benefit.  A mix containing higher contents of Oxygen also requires less surface interval time in between dives as a similar air dive or you gain more credit toward your next dive in the fact that you absorbed less Nitrogen.  The added Oxygen also works to help "off gas" the absorbed Nitrogen faster.  Make since?  Think about it.  What is basic first aid for DCS (the bends)?  Oxygen, right.  So diving with extra oxygen in your breathing mix is kind of like checking both ways before you cross the street.  Don't get hit by a truck and go to the hospital and then later finish crossing the street.  Just don't get hit by a truck.  
Another great benefit is the highly increased bottom times for repetitive dives.  The lower amount of absorbed Nitrogen greatly increases the bottom time for dives two and three.  Sometimes tripling the adjusted bottom time.
More than one out of three divers claim to feel better and less worn out after a day of diving Nitrox.  There is no real scientific proof that such a small increase of Oxygen is not really enough to add other beneficial effects.
Lastly all the tekkie stickers look cool.  Just kidding. :}

Is it safer?

Erm, well, hmm, the general answer is no.  All of the same scary stuff that exists with breathing compressed air still exists when diving Nitrox.  
One way that it can be safer in our area (generally 100' dives) is that divers who have great air consumption rates have a bigger chance of accidentally going into "deco" when using larger volume tanks filled with air.  The extra time provided by Nitrox can help divers avoid this.  This is one reason that we see so many large volume tanks with Nitrox stickers.

What is bad?

Its not really bad but dive planning can be a little more complex in that you have to use the right mix for the right depth.  The more Oxygen in the mix the shallower you have to dive.  Nitrox is best when used 50' to 110'.
Then there is that Central Nervous System Toxicity thingy.  Yeah this is bad.  Rarely found in recreational divers CNS Toxicity can cause convulsions underwater.  "Not good, Mav."  
This happens when divers dive too deep on the wrong mix or dive too many repetitive dives exceeding or reaching maximum limits.  It's simple don't dive a dose above 1.4 pp02.  If you don't know what that means then take the class.   ***Click Here for Nitrox e-Learning***

Some divers push it by diving a dose of 1.6 ppo2.  This is not wise and is only to be used for contingency (emergency) planning or Deco for Tec Divers.  Not recreational diving.  After 45 minutes of high ppO2 (too deep for the mix) your chance of winning the CNS Toxicity lottery is almost 100%.  This is cumulative for every repetitive dive.  So in theory if you dive over a 1.4 ppo2 it could happen on one dive.  
(trust me I know) 
Look at the 1.6 ppo2 row at the bottom ==>NOAA Exposure Table  See?

The other down side is that it can be harder to get, so if you are diving out of a jungle hut don't expect the tank kid to use his bicycle pump to whip you up a batch of Nitrox. 
Not everyone can blend nitrox so you may have to wait for the blender to fill your tanks.
Also it's not cheap. It can cost up to three times the cost of an air fill.

How do I use it?

Order the right mix. (see your course materials for determining the "best" mix)
Analyze the blend yourself. Remember you are changing basic dive physics.  Trust nobody.
I only trust my analyzer so its a good idea to have your own.  We like the Oxycheq Expedition, its small, cheap, and easy to use.
Sign a nitrox log, label your tanks, check the maximum safe depth on your computer or chart and go diving.

Our general diving area makes it simple when it comes to choosing mixes.

You will find yourself either diving around a 100' (Navy Tug, Notch, Bridge Rubble, Liberty Ships, and Tanks) or 130' (the Oriskany, Trysler, Avocet) so diving here you only really need to be concerned with two mixes EAN32 and EAN28. (shoosh, tec divers, see above)

The best mix for depths up to 110' is 32% the MOD for 32% is 111'
The best mix for depths up to 130' is 28% the MOD for 28% is 131'

 Before posting remember this is a light hearted discussion about the Voodoo gas.

Thanks and be safe out there.


Our friend...

Our underwater realm has lost one of its most passionate ambassadors and role models, PADI Instructor Harlon R. Smith Jr.

I will never claim to have been Harlon’s best friend. I only met Harlon at the end of 2005 through a mutual friend and long time dive buddy, Tom Velie. The first thing that I noticed was his infectious smile and great attitude. Harlon had a way about him. He was very easy to be around and everyone flocked to him. Including me. He had that quality of leadership that all we Scuba Instructors desire. I remember thinking this guy would be a great instructor.

After dragging Harlon around the various wrecks in the Gulf of Mexico for a year, I finally coerced a “at the time” very prone to motion sickness, Harlon to follow me on a trip involving small planes, small boats, and bouncy conditions in a third world country in Central America. I mention this because when I met Harlon at the destination it was the only time he didn’t have his smiley face, because of the aforementioned small planes, small boats, and bouncy conditions, but we all laughed about it and had a great time. The week lead to some amazing adventures including the greatest night dive ever with huge dog toothed snapper and 6’ long moray eel that accompanied us the entire dive, the distant electrical storm lighting up the night giving us quick glimpses of the surrounding reef, the flight of rays that seemed to fly in and land in dust clouds like aquatic butterflies, Doc’s Tec dive to 101’, and Tom’s nurse shark attack (not really, yes really). At the end of the week Harlon asked me the question “What would it take to become a Scuba Instructor?” Little did he know, he already had the attitude and passion, we just needed to add some certifications.

Over the next two years Harlon made time to complete the challenging quest of becoming a PADI Master Diver then Certified PADI Divemaster. I say challenging because Harlon had a busy career, amazing family, and 400 mile drive to contend with his time to make it through his training. For those of you that knew Harlon, you know that there are very few people on this planet that possess the passion and willingness to commit one’s self to accomplishing a goal as Harlon Smith Jr. and he did, almost effortlessly.

It was two years later that I received a phone call from a very proud and excitable Harlon. I will never forget the sound of excitement and gratitude in his voice minutes after completing his instructor exam in Destin, Florida. I smile when I say I felt like a proud father, but I did. Its funny because Harlon was 360 days older than me. He thanked me for making his journey easy. I remember telling him. “It was always there I just nudged you in the right direction, you did this. Thank you for being so passionate about the sport and easy to teach. Congratulations, brother and welcome aboard.” Harlon was like a sponge, he took it all in. I loved having him in class. I even got a call from the most experienced Instructor Trainer that coached him the last four days of the course to tell me that he was one of her favourite students. I was told later that Harlon scored amongst the highest out of the group. We had no doubt. After certifying Harlon as an assistant instructor I had met all qualifications to obtain the highest rating available to a Scuba Instructor, the PADI Course Director. So in a way Harlon helped me get my certification.

I liked being around Harlon, he always reminded me of what was important in life. I had and still have a tendency to forget what is most important. My career takes up allot of my time and I seem to never have (or make) time for things that needed my attention. Harlon taught me that the time is there, make it. Absolutely nothing is more important than faith, family and friends. Harlon was also a man of conviction and always did what he said he was going to do to the fullest of his ability. I also learned from Harlon that if you treat everyone fairly and with respect people will remember this about you. One may never know how your interactions with someone may change the course of their life, and even the smallest gesture or guidance can plant a lasting seed that can grow into something amazing. We all have someone that has done this for us in for us and they may or may not even know that they helped shape a part of our lives. This is even more so important for the professional instructor as we have a “captive” audience to force our theories and opinions on. Our behaviours whether role model or not so role model may have a waterfall affect that we could never be made aware of. Meeting Harlon’s dive buddies and students told the tale, he had done it right. His infectious passion for diving had been instilled in them. Stories of diving with Harlon lit up their faces. I saw his smile and joy for life in them. He had taken them on that great adventure and given them that sense of accomplishment that only the best instructors can do.

This is who Harlon was to me.

I will remember my friend fondly every time that I share the Instructor’s Creed with new Instructors, for in my mind he exemplified it.

Instructor's Creed

As a scuba instructor, I have the opportunity to see:

Fear change to courage

Faint-heartedness converted into accomplishment

Timidity transformed into confidence

As a scuba instructor, I can:

Open hearts and minds to the hidden beauty of nature's creation and our obligation to protect it

Foster self-esteem in another person

Teach the value of character and integrity

Transform another human being and change a life for the better and forever.

-Bryan Eslava