Diver Claims: 148 dives to 100 ft in one day

[MaxBottomtime]

I had to look it up. I had never heard of anyone attempting that many deep free dives in one day, but it is possible to get bent. You learn something new every day.
Decompression And Freediving – What Are The Real Risks? - DeeperBlue.com

 

[John C. Ratliff]

Here is a recent study of a male Ama diver in Japan:

Wilderness Environmental Medicine, 2014 Sep;25(3):258-62.
doi: 10.1016/j.wem.2014.02.002.Epub 2014 May 29.
Doppler detection in Ama divers of Japan
Frédéric Lemaître 1, Kiyotaka Kohshi 2, Hideki Tamaki 2, Kasuo Nakayasu 3, Mesanori Harada 3, Masanobu Okayama 3, Yuka Satou 2, Michiko Hoshiko 2, Tatsuya Ishitake 2, Guillaume Costalat 4, Bernard Gardette 5
Affiliations

• PMID: 24882656
• DOI: 10.1016/j.wem.2014.02.002
• . 2014 Sep;25(3):258-62.

doi: 10.1016/j.wem.2014.02.002.Epub 2014 May 29.
Doppler detection in Ama divers of Japan
Frédéric Lemaître 1, Kiyotaka Kohshi 2, Hideki Tamaki 2, Kasuo Nakayasu 3, Mesanori Harada 3, Masanobu Okayama 3, Yuka Satou 2, Michiko Hoshiko 2, Tatsuya Ishitake 2, Guillaume Costalat 4, Bernard Gardette 5
Affiliations

• PMID: 24882656
  
• DOI: 10.1016/j.wem.2014.02.002

Abstract


Objective: Symptoms consistent with neurological decompression sickness (DCS) in commercial breath-hold (Ama) divers has been reported from a few districts of Japan. The aim of this study was to detect circulating intravascular bubbles after repetitive breath-hold diving in a local area where DCS has been reported in Ama divers.

Methods: The participants were 12 partially assisted (descent using weights) male Ama divers. The equipment (AQUALAB system) consisted of continuous-wave Doppler with a 5-MHz frequency, and the Doppler probe was placed in the precordial site with the ultrasonic wave directed into the pulmonary infundibulum. We carried out continuous monitoring for 10 minutes at the end of the series of repetitive dives, and the recordings were made on numerical tracks and graded in a blind manner by 2 experienced investigators, according to the Spencer Doppler code.

Results: Depths and number of dives were 8 to 20 m and 75 to 131 times. Mean diving duration and surface interval were 64 ± 12 seconds and 48 ± 8 seconds, respectively (mean ± SD). We detected the lowest grade of intravascular bubbles (Spencer's grade I) in an Ama diver whose mean surface interval was only 35.2 ± 6.2 seconds. His mean descending, bottom, and ascending times were 10.4 ± 1.6 seconds, 39.2 ± 8 seconds, and 18.2 ± 3.0 seconds, respectively, over the course of 99 dives.

Conclusions: Intravascular bubbles may be formed after repetitive breath-hold dives with short surface intervals or after a long breath-holding session in Ama divers. Symptoms consistent with neurological accidents in repetitive breath-hold diving may be caused in part by the intravascular presence of bubbles, indicating the need for safety procedures.

Keywords: Ama divers; bubbles; decompression sickness.

Copyright © 2014 Wilderness Medical Society. Published by Elsevier Inc. All rights reserved.
Doppler detection in Ama divers of Japan - PubMed

SeaRat

 

[Bazzathemammoth]

I know a freediver who got bent. He was doing back to back 40m descents at the time. Thankfully he made a full recovery.

 

[Centrals]

https://theculturetrip.com/asia/jap...the-sea-the-art-and-tradition-of-free-diving/

They didn't do that for fun!
A dying culture?