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Buoyancy Control October 3, 2009

Posted by Chris Sullivan in Dive Log, Training.
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I recently conducted an Advanced Open Water course with 3 students. One, who I’ve mentioned earlier, just needed to do her navigation dive, so I scheduled that first. The other two had to complete all 5 dives. When students have good diving skills, the course can easily be completed in a single weekend, and often it gets sold with that expectation. But when the skills need further development, these expectations can get shattered, and students can walk away irritated that they didn’t get the card with the amount of effort they expected.

This is unfortunate. Our dive shop has a policy, at least with recreational courses and pretty much with everything, of sticking with the student until they pass. That is and should be different to passing students who can’t complete the requirements, and I for one (for many I hope) wouldn’t do that. Once someone has an advanced card, they are more likely to be taken on deeper dives, and the consequences of poor skills, especially buoyancy control, can be deadly. We could or should, perhaps, be more thorough in assessing the divers’ skills prior to embarking on the course, so we can take remedial action before the pressure to complete the course is fully developed.

Right from the first dive, I realized that the 2 new students would be a challenge. The first stage of the navigation dive is a 100′ out and back swim along a line to measure the number of kick cycles and time. I had two of our divemasters in training set up the course between two large tent pegs at a depth of 20′ after setting the flag. As we are dealing with certified divers, it is fine to send them off by themselves, so I signalled to them to swim the course and marked the time on my watch. As they departed, I had second thoughts about sending them alone, so I signalled to Shannon, my other student who with whom I’d done some previous dives, to come along while I followed them.

Sure enough, one started floating to the surface while the other plummeted to the bottom. Worse still, neither seemed to recognize their situation, and just ploughed along regardless. I finally had to guide them, like I would a first time open water student, to keep them at a reasonably constant depth. Hard work indeed. The remainder of the dive, which I’d now decided to do as shallow as possible and consisting of compass navigation with reciprocal and square courses, was similar, although they had little trouble with the navigation elements.

Unfortunately I had to do the deep dive next. It was getting too late in the day to get three dives in because we’d spent so long on the navigation, and the peak performance buoyancy equipment and nitrox tanks were not coming until the next day. The search and recovery dive is probably the most time consuming  so that left deep, which is quick because of the high air consumption.

For this dive, I stacked the deck by bringing along two divemasters in training. Our trainees are generally excellent divers and a great help, even if not yet certified assistants, and I was much more comfortable having them along. The plan was to swim to our buoy in 30′ of water, descend, and swim straight down a line a far as it goes, to about 85′. I had once of the DMTs take the diver with ear problems down first, so we all wouldn’t have to wait for her during our own descent (as the students are certified divers, it is quite proper to use divemaster trainees for this, or even send them down in buddy teams with no staff). Once I’d seen she was near the bottom, the rest of us descended.

Once the bottom was in clear view, I saw my Eric alone near the line. I made a rapid descent and gave him the universal “what’s going on?” signal (hands at shoulder height and well in front, elbows bent, palms facing slightly toward you, fingers apart and outstretched, with a back and forward movement), and he had me follow him to where she was, about 20′ away waiting for us. Apparently she took it upon herself to take off on him, but never explained why.

I sent him back to get the others, and he returned with the student but not Jody, who was having ear problems.  So the four of us continued down, trying to keep them together so I could watch them both, which is my sole responsibility when deeper than 60′. Needless to say we left a decent silt cloud behind us.

The simple exercises done at depth were no problem for them, but on the way up we both had to work hard to keep them at a reasonable depth. Ascent from 30′ with safety stop, guided by the line, was accomplished without a lot of problems. They seemed quite happy to let me manage all aspects of the dive, including timing the safety stop, navigating, telling them what depth to maintain, correcting their deviations, and so on, and didn’t ask any questions even when prompted.

After the long day was over I discussed the situation at the shop, and the question was “did the complete the required skills?”. I guess the answer is yes, they could complete the advanced tasks, but probably would not have done so without assistance with basic diving skills.

I decide to give it another chance the next day, as I thought the peak performance buoyancy dive would be helpful in tuning up their skills.

By the way, if you recognize yourself in as the students in this story, take heart. Everyone learns and develops skills and awareness at their own pace but it can take persistence and effort.

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Comments»

1. barney - March 12, 2011

except for buoyancy this may not be relevant but the reason I sent it is that after watching these videos http://www.buoyancyquest.com I contacted them with some questions. It turns out that the two divers (they are both instructors) had a combined age of 118 on the day these movies got made…so they fit your title.LOL

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2. Chris Sullivan - March 12, 2011

Rereading this post brings back memories of that dive. The concept of that site looks interesting, and I totally agree with it. For wreck and cave penetration, swim throughs and even just swimming near a silty bottom frog kicking is the only way to go. Streamlining also reduces workload, which for older divers helps a lot and lets us keep up with the younger guys.

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3. chelsea M - March 26, 2011

Thanks Chris! WOW thanks for the link to those videos Barney. I’m only 20. I hope I don’t have to get that old to look that good.LOL

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