Deeper Into Blueholes
 

http://gallery.kiteforum.com/albums/..._Oblique_s.jpg
From: http://www.panoramio.com/user/68388


Dean's Bluehole off Long Island in the Bahamas is a pretty incredible place. The surface of the sinkhole starts at a depth of 18 ft. and descends to 663 ft. The average diameter is 250 ft. Tidal activity creates mild upward and downward currents. A tech diver made the bottom all the way to 663 ft. in 1992! More at: http://www.stellamarisdiving.com/blueholefacts.html


http://www.verticalblue.net/images/gal8.jpg
Note the approximate 60 ft. orifice at 30 ft. deep is substantially smaller in diameter than the rough 250 diameter shaft. It can be a trip descending under negative rock slopes into narcotic depths on compressed air, disorienting to say the least but interesting all the same.
From: http://www.verticalblue.net/

A video clip of the blue hole both above and below the water appears at:
http://tinyurl.com/37ujfw


http://gallery.kiteforum.com/albums/..._Blue_Hole.jpg
The area of the blue hole


In "Morphometry and hydrology of Dean's Blue Hole, Long Island" by
Wilson, W L, Bahamas Journal of Science. Vol. 2, no. 1, pp. 10-14. 1994

"Dean's Blue Hole is an exceptional, world-class, karst feature for several reasons: it is the deepest known blue hole in the world (-663 feet) and is 62% deeper than any other explored cave in the Bahama Islands; the underwater room beneath the entrance shaft is the second largest known underwater cave room and may be the ninth largest cave room in the world; and the volume of water displaced during a tidal cycle indicates that significant cave passages may connect to the blue hole. Simply finding the cavernous passages that may connect to Dean's Blue Hole may be a daunting task because of the size and depth of the room. Elongation of large collapse rooms usually occurs parallel to horizontal passages. Based on the apparent elongation of the room in the east-west orientation, it seems reasonable to suggest that these ends of the room should be examined first. Deep Breathing Systems would be happy to assist other researchers who have an interest in studying Dean's Blue Hole."


More about Bahamian Blue Holes, geology and more at:
http://www.blueholes.org/pubpdf/symposia.pdf


You can checkout a 360 degree panoramic image of the blue hole at:
http://www.bahamas.com/bahamas/biih/index.aspx





http://www.fksa.org/albums/album286/ClearBlueHole.jpg
From: http://www.geocities.com/regkit/



A video clip of a Timo, a freediver heading into the bluehole using a monofin appears below. Sorry for all the tarpon footage, I suspect the videographer hasn't seen that many before. I can recall a large blind one in Warm Mineral Springs, an early man UW archaeological site years back. The sulfur content of the water destroyed diving gear and vision in aquatic life. Now that is a sight to ease out of the dark towards you. There was also a blind alligator too!





Long Island and the bluehole came up in a thread about "Bahamas Week At the FKA!" There is still more good stuff about the Bahamas and sinks at: http://fksa.org/showthread.php?t=4167



http://upload.wikimedia.org/wikipedi...s_20110210.JPG
From: http://en.wikipedia.org/wiki/Dean's_Blue_Hole




.

http://www.fksa.org/albums/album286/Trubridge.jpg

A world record free dive occurred in this blue hole in May 2007. William Trubridge of New Zealand made it to 83 m or 273 ft. without fins, weights or pulling down a descent line. He just moved past Martin Stepanek's record of 81 m set two years ago in 2005.

http://www.amphi.cz/images/nanadech.jpg
Martin coming up in yet another discipline constant ballast, into a Czech documentary

I recently took a freediving course with Martin, lots of interesting new and good ideas on how to do something that has been second nature for a very long time. The first morning in the pool, guys were holding their breaths for over 3 minutes (static apnea). One new student recently, just a regular guy to look at him with no unusual background (shoots fish?) held his breath for 5 minutes and 20 seconds just by following the techniques Martin described. A few others in that class went over 4 minutes I recall. This is static apnea, or floating face down in a pool motionless not swimming.

It involves a lot more than simply increasing your breath hold duration, there is also a lot of training on recognizing problems in yourself and buddy like shallow water blackout and how to avoid it and response should signs appear. When you push out the envelop it is good to have modified procedures to help see you back to the surface. Martin's ideas take a lot of the randomness out of passing out or not on extended freedives.

It looks like Martin recaptured his record recently in Egypt. More about that at:

http://fksa.org/showthread.php?t=4520

I spoke to Martin about it today on a dive. It is amazing all the energy and planning that go into these attempts. He described this cave at about 170 ft. that passes from the sink hole into the Med. He paused on ascent for a photo op! Hey, it's casual, right?!

Look at my Hole Rick!
 

I just saw this one surfing the net today.

http://ambergriscaye.com/pages/town/greatbluehole.html

Came across more images from this intriguing place ...

http://www.prlog.org/10052756-freedi...-blue-hole.jpg
From: http://www.prlog.org/


http://www.verticalblue.net/images/f...freediving.jpg
From: http://www.verticalblue.net/


http://www.blueholebay.com/images/presspic.jpg
From: http://www.blueholebay.com/

Hope to make it out there this summer from a close up look.

holding my breath
 

So Rick, What ARE the techniques for the static hold? Give us a quick course.

Frank

Hey Frank,

Tacked your response to the bottom of another threat at:

http://fksa.org/showthread.php?p=34148

Alright Im sold! When do we go?

I would like to hit it before the end of the summer. JP offered to fly down there for an overnighter. Or, you could go via Nassau and Bahamas Air but the connections and flight time are more tenuous and time consuming. Kent was interested as well, wonder if he still is. It gets dodgy with tropical wx right now and yet this is the time we have. Any interest in shooting for sometime in August? There is a low chance of useable wind, which should be good for visibility in the sink.

http://hphotos-snc3.fbcdn.net/hs468...._6042867_n.jpg
http://www.facebook.com/verticalblue


Thanks to Clinton Bolton, just found a new video clip that shows off some intriguing aspects of Dean's Blue Hole. Guillaume Nery is having fun with some unusual sequences playing off the unusual geology of this remarkable blue hole. Guilaume made 115 m CWT or Constant Weight Apnea (snorkeling gear) in the recent Vertical Blue contest.