Ascending faster than 60ft/minute

[Walter]

I've read that going much slower than 60ft/min has no discernable benefit -- that it hits a point of disappearing returns.

Where did you read it? Was it someplace that can be trusted? I was taught 60ft/min as well, but that was over 20 years ago. I now use 60ft/min as an emergency ascent rate and teach 30ft/min as the recommended rate.

 

[Fish_Whisperer]

I'll go through my books tonight, Walter. I can't remember where I read it...

 

[uglyredshoes]

I guess whatever the rate is, just check it with what Divecomputer you're using. I think the Suunto tables are all 60ft/min regardless of dept, while Oceanic/Aeris have theirs differentiated by deeper than/shallower than 60ft.

 

[japan-diver]

There have been numerous studies over the last several years showing that 60ft per minute was too fast one done by DAN and one by the US Navy to name a few. The recommended rate of ascent by most of these studies have shown 30-40ft per minute to be the upper acceptable range and most reccomending a slower rate of 20 ft per minute or so. The 60ft per minute rate has no scientific basis but was a comprimise speed when the original USN Diving Manual was written- now they have even changed their proscribed rate- and those of us who served in the military knows it takes quite a bit for the military to change anything.

For those defending the 60ft per minute rate I would love to see a current reference that defends it with some scientific studies.

 

[uglyredshoes]

There have been numerous studies over the last several years showing that 60ft per minute was too fast one done by DAN and one by the US Navy to name a few. The recommended rate of ascent by most of these studies have shown 30-40ft per minute to be the upper acceptable range and most reccomending a slower rate of 20 ft per minute or so. The 60ft per minute rate has no scientific basis but was a comprimise speed when the original USN Diving Manual was written- now they have even changed their proscribed rate- and those of us who served in the military knows it takes quite a bit for the military to change anything.

For those defending the 60ft per minute rate I would love to see a current reference that defends it with some scientific studies.

Just curious, we cant change the ascend rates in our dive computers.

How then can we gauge this 20ft/min?

 

[Fish_Whisperer]

Someone on here had a good sig line... (It may have been Walter) "The smallest bubble shall beat me to the surface." That seems a pretty good guideline, to me.

Also, I generally do a 3-minute safety stop at the end of each dive, and then ascend as slowly as possible, once the stop is finished.

 

[ianr33]

I am not sure but i was reading an ATOM dive manual, calculated according to PADI standards. 30ft/min is the ascend rate for depts greater than 60ft. Anything shallower is generally calculated with the ascend rate of 60ft/min.

Interesting concept. Slow ascent rates at depth and faster ascents near the surface????

 

[Walter]

How then can we gauge this 20ft/min?

At 20ft/min, it should take you 3 seconds to ascend 1 foot. That's extremely slow.

Someone on here had a good sig line... (It may have been Walter)

It wasn't me.

 

[uglyredshoes]

Interesting concept. Slow ascent rates at depth and faster ascents near the surface????

HA TYPO!!!!

Thanks for pointing it out!

Yup it should be the other way around. I've edited it! phew

 

[Fish_Whisperer]

It wasn't me.

Hrmmm.... Anyway, it was a good line.