https://www.aa.com.tr/en/sports/turkish-diver-sahika-ercumen-breaks-world-record/1628524

I never knew there were records of such things but she has just broken the world record.............

Eeeek -  :blink:

100m depth down and back up.

Or 100m along roofed passage??

or just 100m 'lengths' back and forth.  (and if so, why in a cave?  :-\ )

It seems the record is distance swum without fins (thus the photo in the original citation is misleading).  The location happened to be in a cave, but the swim was in a lake, not an overhead environment for diving purposes.

Free diving is a bit like caving in that its super niche at least in the UK. But they take records super seriously and have loads of different disciplines. 100m deep is not uncommon in competition and the record at the moment for just swimming is 130m with 253.2m being achieved when they use a sled and just hang on.