Hull cleaning dangers

[sveinung]

A poorly serviced set of scuba regs pose a threat for co2 buildup that can be narcotic or hazardous even at normal ambient pressure, guessing you can add lung edema to the mix as well if you want to be even more creative.
Both are due to high breathing resistance (think straining yourself to suck in the air or inhale through a straw), but pretty sure you'd notice the discomfort and surface before anything got close to dangerous

[belizesailor]

Originally Posted by stillbuilding

I ask because in conversation with a knowledgeable friend he mentioned that his brother nearly died when he was hyperventilating and then competing in underwater swimming. Lost consciousness and lucky to be pulled out of the pool by a friend. I was wondering if similar could occur with the exertion of cleaning the hull even with hookah.

What you describe is not a "hyperbaric" (pressure related) risk. There is effectively no hyperbaric risk at such shallow depth. Standard tables for related calculations dont even start until over 33' (1 atmosphere) and then the no decompression limit is over 200 minutes.

hy·per·bar·ic /ˌhīpərˈberik/ adjective of or involving a gas at a pressure greater than normal. No

There are other risks of course, like the accident you describe above. So an observer, who is capabale of taking appropriate action, should always be present.

What you describe above is often refered to as " shallow water black out".

https://en.m.wikipedia.org/wiki/Free...water_blackout