33 replies to this topic

[Marvel]

Review the old thread. Slow ascent rate is good to a point, but adding safety stops is better. It is better to do a safety stop and add a deeper one and ascend at the computer's rate than to dramatically slow ascent and not do the safety stops. Even really slow to a single safety stop is not as good as a shallow and deep stop with controlled ascent rates. The data is clear that super slow linear ascents as not as good as ascents at faster rates with stops. FYI

True. Neglected to be clear on having added additional safety stops as well. I just tend to disguise them with my diving partners (good way of sucking them in)- so what do you guys say to combining the two? And, what is the source of your data? Something readily understandable to non-dive/science geeks, I hope?

[Diverbrian]

I know the source, but I will let Grant or Trace explain it as they seem to find the words more easily. It does come down to tracking nitrogen bubbles in the blood with ultrasound and comparing the bubbles left after test dives done in various ways.

[bigblueplanet]

M, it is actually as old as the concept of dive tables. It all started with the Hill and Haldane work to win the contract with the Royal Navy. Haldane did stops at half depths and hill did linear ascents. Hill's test subject got bent badily. Haldane's did not. He won and we forever have Haldanian talk and theory. In a nutshell, simple enough?

This idea has been followed up on in recent years. Dr. Bennett was hot on it before his departure from DAN. So, for layperson info read on DAN's site about it. Couple of articles in Alert Diver a few years back.

I believe a bunch of it has been replicated with doppler, but I do not know the reference off the top of my head. Have a ton of trivia in their, but remember the substance not the details. I think DAN may have moved on this. I am sure they will one day.

Combining the two is fine. Just how slow is slow. I think hiding it as you say is a good technique. Of course, that is why I say just plan multilevel dives. That is the same thing. Plan so there is at least a delay at half depths. But, no harm in doing more levels. I will say from 15 feet super slow is definately good. Pure physics on that one. I know I have done it well when I see the rest of the group looking down at me from the surface wondering what is taking me so long. That is diving for fun of course. Just a slow menadering ascent to the surface. Even better if it is on the reef and get to see all the cool stuff everyone races by to go "deep" LOl

G2

[Diverbrian]

M, it is actually as old as the concept of dive tables. It all started with the Hill and Haldane work to win the contract with the Royal Navy. Haldane did stops at half depths and hill did linear ascents. Hill's test subject got bent badily. Haldane's did not. He won and we forever have Haldanian talk and theory. In a nutshell, simple enough?

This idea has been followed up on in recent years. Dr. Bennett was hot on it before his departure from DAN. So, for layperson info read on DAN's site about it. Couple of articles in Alert Diver a few years back.

I believe a bunch of it has been replicated with doppler, but I do not know the reference off the top of my head. Have a ton of trivia in their, but remember the substance not the details. I think DAN may have moved on this. I am sure they will one day.

Combining the two is fine. Just how slow is slow. I think hiding it as you say is a good technique. Of course, that is why I say just plan multilevel dives. That is the same thing. Plan so there is at least a delay at half depths. But, no harm in doing more levels. I will say from 15 feet super slow is definately good. Pure physics on that one. I know I have done it well when I see the rest of the group looking down at me from the surface wondering what is taking me so long. That is diving for fun of course. Just a slow menadering ascent to the surface. Even better if it is on the reef and get to see all the cool stuff everyone races by to go "deep" LOl

G2

I keep forgetting about Haldane's goats as we pretty much pass through Haldanian deco theory in favor of more advanced theory now. LOL I remember reading about that as well.

I was thinking that Doppler research was done on this for the RGBM tables out there. Someone is always to push deco theory ahead.

Thanks, Grant!