ricki
09-28-2009, 11:16 AM
A lot of interesting images came out of the recent Freediving Instructors International liveaboard dive trip to the Red Sea. Martin Stepanek and David Cani of FII brought together a bunch of divers from the Czech Republic and some from the USA for a great experience in the Red Sea. Honza Musil of The Lighthouse Dive Center provided expert local knowledge and no end of trip solutions throughout the visit. A series of videos will come out of the trip starting with "The Dive Sled."
Diving sleds have been around for sometime. They are intended to maximize the depth free divers can descend to and ascend from rapidly in some safety with minimal exertion. Essentially the sled is a collection of weights, traveling on a line at variable speed under brake control with a lift bag diver recovery system. It is intended to allow the diver to relax to something resembling static apnea with minimal input control input to facilitate descent and critically ascent within the breathhold interval. All this with varied provisions for diver safety. As a rule the sled carries a great deal more weight and potential for rapid descent in this case where it was intentionally limited to a normal swimming descent rate. More on current records at: http://tinyurl.com/3bpn4t You can see two recent ones that Martin holds there while you are at it.
We were just trying the sled, not remotely attempting to achieve any records hence the shallow depths, during setup of 25 m and trials of 30 m and 50 m. There was a safety diver near the bottom of the sled run on tri-mix SCUBA and at least two safety free divers meeting the sled diver on ascent. Lots of safety considerations go into these things. Have to confess a bit of nervousness on my part, just getting over a pretty serious respiratory infection at the start of the trip that seemed to clear at lightspeed, still was lingering and all the stuff to remember on such dives. There really isn't that much to remember but the mind can be a strange place particularly with task loading? I wore a wide angle video camera aimed upward during my dive. It captured some unusual images and radical line sounds. You may want to turn your volume up for that part of the video.
http://www.fksa.org/albums/album577/sd1.jpg
On the surface, breathing up for the drop.
A mask squeeze incident appears in the video. It is amazing how you can forget something like breathing into your mask. Still with task loading, distraction say like trying to equalize your ears, it can happen. The diver is fine, looks worse than it is. Brett Scaglion, an FII instructor is on the faculty at Barry University in Miami, FL. He was taking field measurements on the free divers each day as a part of a study considering “Chronic Hypoxia and Freediving: A look at oxygen saturation pre and post anaerobic exertion”.* Brett has a cameo in the clip as well.
Here it is ... enjoy!
6802269
pAxfwf7OEn8
(A duplicate on youtube.com)
http://www.fksa.org/albums/album577/sd3.jpg
Turning the air on at 30 m, slowly filling the lift bags.
Thanks again to:
FII, Martin, David, Niki and Bret
http://www.freedivinginstructors.com/
The Lighthouse Dive Center, Honza and the able crew on the MV Miracle One and in Hurghada
http://www.dahabdive.com/
* In Brett's own words ... "Basically, we were looking at chronic hypoxia over an extended period of freediving and also at hydration in an arid environment… we looked at what an individual’s oxygen saturation/heart rate were before they got in the water and then looked at them again as soon as they got out of the water. We were looking to see if individuals replenished their oxygen stores fully in between diving sessions and for the most part, many individuals entered the water with a lower oxygen saturation to begin with on the second and third dives than they had in the morning! The hydration just looked at how much fluid individuals were losing over the period of a dive and if they were able to replenish those stores before the next dive… for the most part, people were able to replenish their hydration."
http://www.fksa.org/albums/album577/sd4.jpg
Blasting towards the surface under dual lift bag acceleration through a constellation of divers in a cloud of bubbles!
.
Diving sleds have been around for sometime. They are intended to maximize the depth free divers can descend to and ascend from rapidly in some safety with minimal exertion. Essentially the sled is a collection of weights, traveling on a line at variable speed under brake control with a lift bag diver recovery system. It is intended to allow the diver to relax to something resembling static apnea with minimal input control input to facilitate descent and critically ascent within the breathhold interval. All this with varied provisions for diver safety. As a rule the sled carries a great deal more weight and potential for rapid descent in this case where it was intentionally limited to a normal swimming descent rate. More on current records at: http://tinyurl.com/3bpn4t You can see two recent ones that Martin holds there while you are at it.
We were just trying the sled, not remotely attempting to achieve any records hence the shallow depths, during setup of 25 m and trials of 30 m and 50 m. There was a safety diver near the bottom of the sled run on tri-mix SCUBA and at least two safety free divers meeting the sled diver on ascent. Lots of safety considerations go into these things. Have to confess a bit of nervousness on my part, just getting over a pretty serious respiratory infection at the start of the trip that seemed to clear at lightspeed, still was lingering and all the stuff to remember on such dives. There really isn't that much to remember but the mind can be a strange place particularly with task loading? I wore a wide angle video camera aimed upward during my dive. It captured some unusual images and radical line sounds. You may want to turn your volume up for that part of the video.
http://www.fksa.org/albums/album577/sd1.jpg
On the surface, breathing up for the drop.
A mask squeeze incident appears in the video. It is amazing how you can forget something like breathing into your mask. Still with task loading, distraction say like trying to equalize your ears, it can happen. The diver is fine, looks worse than it is. Brett Scaglion, an FII instructor is on the faculty at Barry University in Miami, FL. He was taking field measurements on the free divers each day as a part of a study considering “Chronic Hypoxia and Freediving: A look at oxygen saturation pre and post anaerobic exertion”.* Brett has a cameo in the clip as well.
Here it is ... enjoy!
6802269
pAxfwf7OEn8
(A duplicate on youtube.com)
http://www.fksa.org/albums/album577/sd3.jpg
Turning the air on at 30 m, slowly filling the lift bags.
Thanks again to:
FII, Martin, David, Niki and Bret
http://www.freedivinginstructors.com/
The Lighthouse Dive Center, Honza and the able crew on the MV Miracle One and in Hurghada
http://www.dahabdive.com/
* In Brett's own words ... "Basically, we were looking at chronic hypoxia over an extended period of freediving and also at hydration in an arid environment… we looked at what an individual’s oxygen saturation/heart rate were before they got in the water and then looked at them again as soon as they got out of the water. We were looking to see if individuals replenished their oxygen stores fully in between diving sessions and for the most part, many individuals entered the water with a lower oxygen saturation to begin with on the second and third dives than they had in the morning! The hydration just looked at how much fluid individuals were losing over the period of a dive and if they were able to replenish those stores before the next dive… for the most part, people were able to replenish their hydration."
http://www.fksa.org/albums/album577/sd4.jpg
Blasting towards the surface under dual lift bag acceleration through a constellation of divers in a cloud of bubbles!
.