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Back in the Pool February 9, 2013

Posted by Chris Sullivan in Dive Log, Training.
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It’s been a while, maybe almost a year, since I did any pool training. I could have done some of the small things a bit better, but overall it went great and we were pleased. The students were all great and none had any undue anxiety.

Maybe there’s more instructing in the cards for me this year. For once I feel like doing it again. Or maybe it was just the energizing effect of the Nitrox I was breathing (although those effects are not proven, of course).

We had 10 students, two instructors, 3 divemasters, and 3 divemasters in training. Made it easy, even though the DMiTs were doing some of their own exercises.


Diving in the News, Oct 27, 2012 October 27, 2012

Posted by Chris Sullivan in Emergencies, Fitness and Nutrition, Miscellany, Training.
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A La Jolla, California diver died in hospital after losing consciousness on a boat dive. It seems that everything that could have been done was done to save him. The cause appeared to be a medical problem, and the diver appeared to be over 40. From the news at least it seems that the most common cause of death among divers is medical problems with older divers. Fitness would clearly be a good thing, but so might better training and skills. Diving should be relaxing, not physically stressful. I’ve reported on fatalities in La Jolla before. A solo diver died there in September, and a man died on his first solo dive at 155′ a few years back.

SDI Comes to Town March 17, 2011

Posted by Chris Sullivan in Equipment, Technical Diving, Training.
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The owner of our LDS has some SDI and TDI instructor certifications, but has been 99.87% PADI for years. He also has some IANTD certifications, but as I wrote long ago I started the IANTD Advanced Nitrox Course, but switched over to PADI Tec Deep mid way through. All my certs except Open Water Diver are PADI, although I did the SDI Solo Diver course but the card is lost in process somewhere.

Today (writing this on March 5, publishing later) Steve Moore from SDI/TDI gave the instructors and some other pro staff a presentation on their courses and standards, and also showed us some of the products he represents from Edge and Hog, which are recreational and technical product lines respectively. These products are aggressively priced and may be a signal of greater competition in the dive industry.

Edge and Hog Wares on Display

Throughout the presentation Steve gave dive shop pricing, but even taking that into consideration the costs were low. A lot of the gear was styled along the same lines as the Apeks equipment that I use, but parts are not interchangeable. The Hog (technical) regulators were similar to the ATX50, although they also had an end port which is handy for us dry suit divers. I use the Tek 3 these days which has all ports between the valves on the doubles and pointing downward so I don’t have to have a weird routing of the dry-suit hose.

He then started the introduction to SDI/TDI. This started with the announcement that Doug Arnberg was no longer the Eastern Canada Regional Manager. No explanation was given. I imagine I’ll hear the story sooner or later.

Pitching SDI/TDI in a PADI Shop

So here as some of the things I heard that make SDI/TDI different from PADI.

  1. In general, fees and materials cost less. This is why Steve was here in the first place. The problem for instructors though is that we are unlikely to give up our PADI memberships so we’ll end up paying for both.
  2. Open Water courses are computer based. All divers have to have a computer, which means the shop has to have them available for rent. The instructors would like them integrated into the console to cut down on losses. That may not happen.
  3. Training curriculum is similar (emphasis on RSTC standards) but is less rigid than PADI.
  4. Except for Open Water training, more than 3 training dives are allowed per student per day, as long as the dive profiles are reasonable. As many training dives occur in quite shallow water, this is quite reasonable and gives greater flexibility to the instructor. Mind you, students will get really tired after the 3rd dive.
  5. Instructor certifications don’t require Instructor Examinations by the agency.

In the end, the decision will come down to the specifics of deal.

I'm Listening, but Still Not Convinced

Enriched Air Nitrox Formulas February 28, 2011

Posted by Chris Sullivan in Technical Diving, Training.
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Formulas for Nitrox are used for several purposes:

  1. Calculating the Equivalent Air Depth (EAD) to allow the use of standard Air tables to calculated no decompression limits, repetitive groups, or decompression schedules.
  2. Calculating the best or optimum mix for a given depth
  3. Calculating the maximum or contingency depth for a given mix to minimize risk of CNS Oxygen Toxicity
  4. Calculating the oxygen exposure for managing Pulmonary Oxygen Toxicity
  5. There are also formulas for partial pressure filling of tanks, which determine how much Oxygen needs to be put in before topping up with air. A more difficult problem is how much Nitrox to drain from a tank before topping off with air in order to reduce the fraction of O2 in the mix.

In basic Nitrox training we’re given the formulas for 1-3, and a table to manage 4 in recreational diving situations. The PADI table uses the NOAA or “CNS” clock only, with no surface interval credit. Surface interval credit makes sense in technical diving when we’re managing pulmonary toxicity using the Repex method, but when using one table to manage both I’m not convinced that it would be wise to apply it.

Even in basic training, I usually like to point out why the formulas work, instead of using rote learning.  I first starting doing this when I took the course myself in the Turks and Caicos in 2005, and found that the understand helps me both remember the formulas (which I’ve never been good at) and to catch errors in my calculations.

Except in case 5, all of the formulas relate to the pressure of Nitrogen or Oxygen in Absolute Atmospheres. Everything that in Imperial divides, multiplies, adds or subtracts 33 (or 34 in fresh water) is converting between gauge and absolute atmospheres, and the formulas themselves are much easier to remember in ATA than in ATG.

Hard to imagine February 28, 2011

Posted by Chris Sullivan in Training.
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This story of a the death of a 28 year-old woman is troubling. As with most stories like this, there aren’t enough facts to really form an opinion. The woman was with an instructor in Fiji, but the instructor surfaced without her. She was later recovered and her boyfriend tried to revive her. It doesn’t mention what she was doing with the instructor or how many other divers were with them. Based on the article, one might wonder:

  1. How could an instructor lose track of a student in the clear waters of Fiji?
  2. Why wasn’t the EFR trained instructor involved in the resuscitation?

PADI is investigating and well they should, at least based on this story.

After writing this I noticed another story this time describing the instructor as a “dive master”, and that he surfaced to change cylinders. If she was with a buddy, and was sufficiently experienced, that just might have been reasonable if conditions were good. But the article goes on to describe strong currents. This one also reports that the boyfriend gave CPR rather than the “dive master”, which is odd.

Goes to show that precision reporting on dive accidents doesn’t occur in the mainstream press.

MOD Memory Aid September 17, 2010

Posted by Chris Sullivan in Technical Diving, Training.
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Maximum Operating Depth and Contingency Operating Depths for Nitrox diving are defined (by most) as the depths you reach PP02 of 1.4 and 1.6 respectively, indicating the recommended safe limits for continuous Oxygen exposure during the working and deco portion of a dive.

When I was teaching a Tec 40 class we were discuss MODs and other depth and pressure related calculations and I was using the formulas to explain the principles behind the math, the instructor mentioned Daltons’ Diamond, which I had to confess not remembering. It looks like this:

     /  \
  /    |   \
 /Depth| FO2\

It says that Depth*FO2=PP02, PPO2/Depth=Fo2, and PP02/FO2=Depth. The trick is that depth is in Absolute Atmospheres, so you need to divide FSW (feet of sea water) by 33, FFW (feet of fresh water) by 34, MFW (metres of fresh water) by 10, etc, then add 1. For instance, 50% mix at 33 feet is FO2=.5, Depth=2, so PP02=1 (and safe).

The memory aid is simple for people who used computers, and useless for those who do not. The triangle is made up of the first initials PDF (PPO2, Depth and FO2), which is the file format used by Adobe Acrobat.  Once I noticed it I never forgot it, and neither do my computer-using students.

Tec 40 Graduation Dive June 29, 2010

Posted by Chris Sullivan in Dive Log, Shipwrecks, Technical Diving, Training.
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Rather than end up at our usual mud hole, on June 13th 2010, the Tec 40 students, assistants and instructor met at Caiger’s Resort along the mighty St. Lawrence River to knock off the class’ first (authorized) decompression dive. With 3 students, an instructor and 2 assistants, we had an easy time of it, with the students forming a team, but also being buddied up with a certified pro to both harry them and be around for emergencies.

The location was Ivy Lea Ontario, just a little upriver from the Thousand Islands bridge. I’d been there once before, and having enjoyed it the first time, was looking forward to doing it again. The dive consists of dropping into the river about 1/2 way along Ash Island, then drifting to a wreck known as the Ash Island Barge.

Once we’d entered the water, gathered together and done our bubble checks, we dropped over the wall to our planned depth of 125′. Actually Dave went a bit deeper to see if the students would follow him. They did, but soon caught themselves and got established at the proper depth. About 1/2 way through the drift we stopped and went through some drills, then continued on to the barge.

By the time we got there, we were almost out of time, so a couple more quick procedures and we headed up for our deco. Each student performed a gas switch on the way up to their decompression stops and soon thereafter our new graduates were floating on the surface where the boat was waiting for us.

Graduates waiting to be picked up

Because I need to log some 130+ deco dives to qualify for Tec Instruction, I followed Dave down to 132′, and used EAN50 for staged decompression. Water temperature was 15C (58F) on the bottom. We’re looking forward to diving the St. Lawrence again with some new students on Saturday. It should be even warmer.

Tec 40, First impressions April 8, 2010

Posted by Chris Sullivan in Technical Diving, Training.
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The DSAT Tec Deep course I took a 3 years ago has been split into 3. The course is essentially the same when you put all 3 modules together, except that there are now incremental certifications on the way to the full 50 metre/165 foot, 100% O2, 2 deco bottle certification.

The 3 courses are Tec 40, Tec 45, and Tec 50, referring to the depth limits in metres for each level. My local dive shop just started a Tec 40 course, we me as the certified assistant. Each level consists of 1 confined water dive and 3 open water dives.

Tec 40 retains the 40 metre recreational limit, but allows up to 10 minutes of unaccelerated decompression, and enriched air mixes up to 50%.

Tec 45 goes a little deeper and permits a single deco gas up to 100%, while Tec 50 teaches two gas decompression (something I have found fairly useless in most (but definitely not all) air diving scenarios.

There are a few loose ends and contradictions. The knowledge reviews are in separate handouts which jump back and forth in the manual, which hasn’t changed from the original course. Worse,  there are places where the standards contradict themselves. One that we’ve already run into in Tec 40 says in one place that deco gas carried by students can never exceed 1.4 PP02 at the deepest part of the dive, while another says that if students are carrying mixes that are beyond 1.4 PP02 for decompression to make sure to remind them of the hazard and proper procedures.

Given that the course is supposed to allow for up to 50% Oxygen to add conservatism to decompression (as we are not talking about accelerated decompression), restricting to 1.4 means the dive can’t exceed about 60′, which renders it useless for practical purposes.

Hopefully these issues will get sorted out with time, and the student materials will catch up with the curriculum. Whilst the Tec Deep had the advantage of a cost-effective way to go through what would be 3 courses with any of the other agencies, the new packaging seems popular with many of the students, some of whom find committing to the entire program to be a bit daunting.

Promotion December 22, 2009

Posted by Chris Sullivan in Training.
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I certified 3 new divers on my recent trip to the Florida Keys. One was an advanced open water diver and two were in the deep specialty. This allowed me to upgrade my PADI status to Master Scuba Diver Trainer (MSDT), catching up with my fellow instructors.

One benefit of MSDT are that you can apply directly to PADI for specialty instructor ratings, which I did immediately for everything for which I qualified. I’ve heard of instructors doing this without the necessary 20 dives “in the specialty” but I’ve been honest. The biggest temptation was night diving, of which I’ve done a limited amount but have more experience in equivalently dark surrounding during daylight hours. Some of the ratings seem more in the “card collector” category but others will be useful as long I can find students. I’m looking forward to teaching underwater navigation for instance, as this is one of the key diving skills.

MSDT is also a prerequisite for some other things, most notably technical diving instruction. I’ve a long way to go in this, having to act as an assistant to another instructor, getting a few more Nitrox/Deep certifications, and some more deep staged decompression dives in but it will all come together in a year or two I think.

So at any rate I’ve now earned 14 specialty instructor ratings, which are:

  1. Deep Diver
  2. Digital U/W Photographer
  3. Drift Diver
  4. Dry Suit Diver
  5. Enriched Air
  6. Emergency Oxygen Provider
  7. Wreck Diver
  8. AWARE Fish ID
  9. Boat Diver
  10. Multilevel Diver
  11. U/W Naturalist
  12. U/W Navigator
  13. Search & Recovery Diver
  14. U/W Photographer

Some of the dives I used to qualify for Navigation and Search & Recovery Diver were looking for things I’d lost on the bottom of the Lake.

Solo Diving Together November 3, 2009

Posted by Chris Sullivan in Dive Log, Training.
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No, this isn’t a harangue about “same day, same ocean” dive buddies. I’ll save that for another time. On Saturday (October 30th) we headed up to Big Bay Point to finish our solo diving course. The purpose of the in-water exercises is to promote self sufficiency. For this reason, we spent some enjoyable moments having our air shut off, are masks removed, and ourselves entangled in line.

We all had our own issues. I’d not thought everything through properly. I took the backup reg set from my technical setup for the AL80 on my back, and one of my deco regs for the pony. I’d not realized that this would only give me one LP inflator, which meant that with my dry suit I’d have nothing to use for my BC. It had been 26 years since I’d dived using oral inflate only but rather than switching over to my recreational reg with its “extra” second stage, I decided it would be good practice to try it on this dive. Despite what you might read about *OMS) bungeed wings being impossible to inflate orally, I had no problem with it, although I did have to blow a little harder than with a regular wing.

After dropping my pony bottle (more like a quarter-horse bottle as I used my Faber steel 45) on the bottom, I did my giant-stride off the end of the dock and releasing the minimum amount of air to submerge, fetched it and hooked it on to my BC while swimming out to the descent line.

The first exercise was replacing my mask with my spare. I was glad to do this as while I always carry one, I’ve never actually practiced replacing it. I didn’t find it difficult, although it took a while to get the pocket open, retrieve the mask, orient it properly and put in on. The first time through this exercise we were on the bottom. Following that we did the out of air drills. This didn’t go so well. Inadvertently I’d looped the regulator hose around the bottom clip, so it would not pull out. So I had to lean forward to keep the reg in my mouth while I unclipped the tank to free the hose. Manageable, I suppose, but not something you’d want to have occur in a real out-of-air situation.

After that, we did the same drills while swimming, with our friendly divemasters shutting our air down or removing our masks at various times. The hardest thing was maintaining depth without a mask. I could feel the air expanding in my dry suit and quickly moved to dump some air. I felt like I was still ascending but emptied my lungs and found that I was at about the same depth once my mask was back on as when I started. Looking at my computer log it there only seems to be small incursions so my perceptions were no-doubt amplified by my imagination.

Solo Dive

We also had lines tied around us and masses of silt blinding our vision. Perfect for a day’s outing. Both the water and the air were about 11 degrees C (52-53 F). There was little evidence of a thermocline down to 63 feet, although I’m sure we would have hit one if we went a little deeper.

That’s fall diving in Ontario, and why we like our dry suits.

BBP 20091029

Anyway, congratulations to Marty, Steve, Rich and Carlos on becoming SDI solo divers.