It does happen, but usually it's not a problem if they don't do it too often. The amount of nitrogen in a single breath of air is pretty small and their time at depth is very short. Repeated dives can increase the amount of dissolved nitrogen though. This can be a problem especially if they have a heart defect called Patent Foramen Ovale which allows bubbles to bypass the lungs directly into arteries heading to the brain.
For instance, for a 140ft dive, the no decompression limit for SCUBA (The amount of time you can stay at that depth without making stops at shallower depths to remove nitrogen) is 5 minutes. The typical no limits free dive is 2 minutes.
They do experience a mild case of the bends on every dive but never notice it because it's so minor.
For instance, for a 140ft dive, the no decompression limit for SCUBA (The amount of time you can stay at that depth without making stops at shallower depths to remove nitrogen) is 5 minutes. The typical no limits free dive is 2 minutes.
They do experience a mild case of the bends on every dive but never notice it because it's so minor.
https://www.mayoclinic.org/diseases-conditions/patent-forame...
https://divetables.com.au/dive-tables/