Suunto Eon Steel Skipped Safety Stop

[DevonDiver]

You hit my point exactly. I even stated in an earlier post that I never violated PADI standards and never exceeded 60ft/min. This only happened on the CESA exercise where students tend to try and move faster than something like an alternate air source ascent. So by PADI standards this was not a rapid ascent, but for Suunto’s RGBM it was. So which one is right?

1. PADI do give advice on that in the OW materials and 'guide to computers'.
2. If diving PADI tables, 18m/60ft applies. If diving computers, the computer max ascent rate applies.
3. PADI will state it's the instructors' role to control and ensure the student does not exceed ascent rates.
4. 9m per minute over 6m is 40 seconds / over 9m is 1 minute. That's hard for most students.

The fact is that PADI is the only agency that accepts 18m/60ft per minute as a max ascent rate. 9-10m per minute is the standard max rate for every other agency AND every computer manufacturer. What this means is that other agencies do not ask instructors to conduct swimming/buoyant out-of-air emergency ascents in open-water; they are practiced in confined water only.

Pause for thought... I'd encourage some speculation as to why PADI doesn't fall in line with every other agency and computer manufacturer with regards to max ascent rate and/or conduct of emergency swimming ascents in open water.....

In reality neither is 100% correct. It all comes down to many personal factors including weight, hydration, level of exertion, history of DCS, ext. The list goes on. It all comes down to the level of risk you are willing to accept.

Not really. There is a presumption that DCS is all-or-nothing.... or there is only 1-2 valid models of DCS (type I and II). That 'chamber bent' is all you have to worry about. Hence, DCS 'predisposing factors'.

Those predisposing factors have little bearing on the formation of microbubbles. But will impact on bubble growth to clinical levels (chamber DCS). They also have little impact on the physiological risk of repeatedly growing, then crushing, bubbles through multiple, shallow, ascents and descents. It's the re-descent/s that cause the big problems... crushing bubbles and allowing them to move through tissue barriers that they shouldn't otherwise be able to pass through.... before allowing them to re-grow, merge etc in other areas of the body.

This is where we need to change perspective. No agency should push an instructor into a risk acceptance scenario for the sake of accomplishing that agency's standards or teaching objectives.

I spent the first few years of diving with only an SPG and depth gauge. I relied on tables and a stop watch.

Yes... and diving on tables/bottom timers didn't provoke any 'alarm bells' (intellectually or on your computer) to ring. This was the situation when PADI originally wrote their tables and theorized their max ascent speeds. Several generations of diving medical research, decompression theory and computer design have occurred since then.

Again, pause to reflect on why PADI's advice on ascent speeds etc did not evolve with that technology and research...