Quote:
Originally Posted by conchxpress
Rick, sounds like a great course, but pretty technical sounding. I think we need a glossary of terms.
1. Packing
2. Reverse Packing
3. Negative Pressure Dive
4. Kick Cycle Exercises
Frank
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Good questions and my mistake for not elaborating. They leave packing for the third in the series of courses on purpose. It expands your ability at a price however. There is a need for greater care, awareness of physiological impacts, buoyancy variation and more. As I recall Martin Stepanek expands his already remarkable lung capacity of 8 liters to
12 liters though packing. Most normal adult males have a lung capacity of around 5 liters if memory serves from the Level II class. All the rest is covered in the FIT II course and used in greater depth in the FIT III course.
Packing is the process by which you expand your retained lung volume of air by compressing air in effect on top of a full inhalation. This allows more air for greater depths, bottom time and equalization.
Reverse packing is applying a vacuum to your lung contents for purposes filling your mouth to provide air for equalization of your ears at depth. Otherwise you will reach a depth below which you can no longer equalize or safely descend.
Negative pressure dive is descending after a full exhalation of air to the best of your ability. It is a good conditioning exercise.
Kick cycles is a useful technique by which you can calculate your depth and for determining when you reach neutral buoyancy and the "sink phase". You calibrate your kicking, in my case dolphin kicks for many others scissor kicks, counting the number to arrive at 33 ' or 10 m. We weight ourselves with full wetsuits and hoods to be neutral at this point and to become negative at 66 ' or 20 m. In my case, without packing with a 3 mm full suit this means NO weight and about 6 kicks to 33'. With packing my neutral depth drops to about 45 ft. and sink phase point to about 85 ft. with 8 and 16 kick cycles respectively. I add one whole pound of lead to help compensate for packing. For messing around above 33 ft. I might have to wear 7 or 8 pounds of lead with the same suit! Another 6 kicks of lesser magnitude and you reach 66' when you start free fall or the "sink phase." It is all about relaxation and economy of motion and air/energy expended. If you don't have to kick to go down (or up) during certain portions of your dive, you shouldn't. This allows more ease and great bottom time and depth capacity. They also focus quite a bit on proper body position to optimize this whole process during descent and ascent. On ascent a bit above 33 ft. you can stop kicking and ride up with minimal exertion.
It sounds complicated, in some ways it is. Still, they give it to you in manageable pieces through time with implementation in the pool and ocean followed by review sessions. As with all things though with repetition both during the course and practice sessions which FIT has frequently, it sinks in. It is a very good way to optimize your abilities underwater for touring shallow to deep, photography, spearfishing and more.
p.s.- worried about having enough air to make these depths and even greater ones? Good you asked. In the Level II course FIT exposes students to natural existing skills through use of proper techniques and safety procedures that can remarkably expand your abilities rapidly. Sound too good to be true? Often enough, it is just how things workout. With all this expanded ability comes the essential need to follow certain safety procedures. One without the other is a very bad idea. I believe some of these safety procedures and rescue techniques should be standard in all SCUBA courses (everyone holds their breath at points, not on compressed air hopefully, and are possibly subject to blackout due to hypoxia). To my knowledge they aren't taught currently in SCUBA instruction.