Monday, February 2, 2015

It looks like he's flying underwater


I'm obliged to Gerard Vanderleun for linking to this fascinating video of French freediver Guillaume Néry 'surfing' the strong underwater currents through Tiputa Pass in the Rangiroa Atoll, part of the Tuamotu Archipelago in French Polynesia.  Wikipedia notes:

Rangiroa offers some of the best dives in the world in and around the Tiputa Pass, which lies at one end of the one main road and runs 3.5 km to the Avatoru Pass. Sedentary common bottlenose dolphins ... regularly play group in the Pass. They can be viewed from the mainland but it is also one of the few places where they can be approached in scuba diving. Because of its large size and the existence of only two passes, each high tide creates a strong incoming current while each low tide creates a strong outgoing current in those two passes. When the current is flowing inward through Tiputa Pass, about 200 shark specimens gather at the entrance to the Tiputa Pass, at fifty meters deep. Led by the strong current, sharks can remain motionless and allow divers to observe them without any difficulty. Large manta rays, green sea turtles, and humphead wrasses can also be seen. Occasionally, tiger sharks and hammerhead sharks can also be spotted. In January, large number of stingrays gather in the Tiputa Pass, as well as hammerhead sharks that feed on them.

I recommend watching the video in full-screen mode.





Peter

5 comments:

Elizabeth said...

Oxygen?? Where is the air pack??

Elizabeth said...

and yes, I understand 'free dive', but really, where is the O2?

Peter said...

I presume the video was filmed over several different dives. There's no way it could be filmed in one continuous shot without an oxygen tank. Could he have taken air from divers accompanying the cameraman?

Old NFO said...

That is an 'eerie' video...

R said...

At less than three minutes it's entirely possible that this was a single breath hold dive. The free diver was not very active and trained free diver frequently are submerged for 3-5min.

Oxygen is sparingly used in diving since it becomes toxic enough to cause convulsions at depths below twenty feet. Divers tanks may contain air, air/oxygen blends (NITROX), oxygen/helium (HeliOX)or air/oxygen/helium (TRIMIX) blends depending on the depth and training of the diver. At shallow depths oxygen is used to displace nitrogen with more gas being replaced with helium as the depth increases.