Quickest path to deco diving?

[Nick_Radov]

Every dive is a solo dive whether or not you are diving with others. You are completely responsible for your own safety and must be self sufficient.

Wrong. You wouldn't say that if you had experienced, properly trained buddies to dive with as part of a unified team. I had had problems on complex tech dives and it sure was nice to have a skilled buddy right there helping out.

 

[Nick_Radov]

I too am Somewhat concerned about comments like "Fastest path to" and "I just don't see much of a big deal beyond a comprehension of deco calculations". I would think that Deco Calculations are a big deal and the calculations are just part of it. As I, understand it, you also have to execute the deco plan with precision as to ascent rate, stop times, leaving the stop on time for the next stop, and managing gas consumption and trim.

It's important to understand deco theory and calculations, but the science is constantly changing and there are still a lot of unknowns. No one has ever performed a proper controlled experiment with thousands of divers executing different deco plans to determine what actually produces the best results. The absolute incidence of clinical DCS symptoms is so low that it's hard to determine to a statistically significant level whether one plan is better than another.

There are also other risk factors which in practice dwarf any minor differences in deco plans. I mean things like adipose tissue volume, circulatory system health (including shunts such as a PFO), body temperature, hydration, etc. So we have to look at the big picture holistically instead of obsessing over minor details.

Absent reliable scientific guidance, I'm skeptical that it's important to precisely execute a particular plan from a deco perspective. I've tried a variety of different deco plans and really can't feel any difference as long as the total time is about right. In other words, if you need to deco for 50 minutes total there's no evidence that spending 6 minutes at 70 ft and 4 minutes at 60 ft is better or worse than 4 minutes at 70 ft and 6 minutes at 60 ft. (But that's just my subjective experience, don't blame me if you get bent.)

In practice the importance of precisely executing a deco plan is more for other reasons. You don't want to confuse your buddies by altering the plan agreed in the pre-dive briefing. You don't want to linger at deco stops and risk running low on gas. You don't want to worry the boat crew if you fail to surface on schedule.

I share your concern about taking the fastest path to deco diving. What's the rush? There's plenty of interesting stuff to see within recreational limits.

 

[Wibble]

Wrong. You wouldn't say that if you had experienced, properly trained buddies to dive with as part of a unified team. I had had problems on complex tech dives and it sure was nice to have a skilled buddy right there helping out.

In your ever so humble opinion.

Only you are responsible for yourself. If you think you're relying on your teammates/buddies/geezer you've decided to jump in with, then more fool you.

Before this descends into a clash of the handbags... The problem with team diving is you're always focussed on the team. If you're relying on them to get you out of the brown stuff, then you have to commit to doing the same for them. This means you're not spending the time you want on the wreck, gawping at fish, taking photos, measuring the boiler, etc.

If you are interested in playing with the fish/wreck then you need to be resilient with sorted skills. If your gas source fails, you simply change to the backup and sort out the problem or you're now ascending with sufficient gas for your decompression obligation.

Skills. Practice. Planning. Practice. Monitoring. Resilience. Go diving.

Not everyone likes diving with other people. If that floats your boat, please fill your boots. Just don't assume teem diving suits everyone.


BTW what happens when you're separated from teammates/buddies? Do you look around for one minute and ascend?

 

[Celt]

You only have to worry about your own reaction to booze and how you intend to deal with it, and the only way to find out is to go drunk driving.

Do you realize how stupid that sounds? I prefer to learn from the mistakes of others rather than putting my own life at risk. Just use the correct mix to keep your narcosis and WOB down to a reasonable level. What's so hard about that? It's disappointing to see divers still promoting unsafe practices like deep air in 2022. We had the same discussions on the old Techdiver email list 20+ years ago but I guess some people will never learn. Sad.

Not half as stupid as comparing alcohol consumption and drink driving to narcosis.

 

[Wibble]

It's important to understand deco theory and calculations, but the science is constantly changing and there are still a lot of unknowns. No one has ever performed a proper controlled experiment with thousands of divers executing different deco plans to determine what actually produces the best results. The absolute incidence of clinical DCS symptoms is so low that it's hard to determine to a statistically significant level whether one plan is better than another.

There are also other risk factors which in practice dwarf any minor differences in deco plans. I mean things like adipose tissue volume, circulatory system health (including shunts such as a PFO), body temperature, hydration, etc. So we have to look at the big picture holistically instead of obsessing over minor details.

Absent reliable scientific guidance, I'm skeptical that it's important to precisely execute a particular plan from a deco perspective. I've tried a variety of different deco plans and really can't feel any difference as long as the total time is about right. In other words, if you need to deco for 50 minutes total there's no evidence that spending 6 minutes at 70 ft and 4 minutes at 60 ft is better or worse than 4 minutes at 70 ft and 6 minutes at 60 ft. (But that's just my subjective experience, don't blame me if you get bent.)

In practice the importance of precisely executing a deco plan is more for other reasons. You don't want to confuse your buddies by altering the plan agreed in the pre-dive briefing. You don't want to linger at deco stops and risk running low on gas. You don't want to worry the boat crew if you fail to surface on schedule.

The main thing about decompression algorithms is they're statistically configured to get most people out from a dive unbent. There's a degree of additional resilience built in to cope with small variations.

What they can't cope with is external factors such as a PFO / poor circulation / illness. They also need adjusting if there are external factors such as cold, exercise, hydration, stress, all summed up as your personal feelings that day.

In essence this may mean you extend your dive to reduce your GF-high before ascending. For example you might dive with 50:80 normally but choose to extend that to 50:70 to mitigate some additional stress during that dive -- high levels of breathing, etc.

Obviously this is a personal thing. If you're diving with others you'll need to communicate that as they'll probably want to hang around; or conversely you need to hang around for them to complete any arbitrary decompression extension.

I share your concern about taking the fastest path to deco diving. What's the rush? There's plenty of interesting stuff to see within recreational limits.

Absolutely. It's not a race. It's a steady ongoing development as you gain experience.

 

[BoundForElsewhere]

the quickest path to deco diving is go too deep or spend too much time at depth. Then you have to do a deco dive.

 

[crofrog]

Only you are responsible for yourself. If you think you're relying on your teammates/buddies/geezer you've decided to jump in with, then more fool you.

No I'm relying on a team of people that have similar skills, mindset, and pre-agreed goals many of which are close friends.

Before this descends into a clash of the handbags... The problem with team diving is you're always focussed on the team. If you're relying on them to get you out of the brown stuff, then you have to commit to doing the same for them. This means you're not spending the time you want on the wreck, gawping at fish, taking photos, measuring the boiler, etc.

Yep we've all committed to taking care of each other and making sure the team succeeds. If the goal of the dive is to measure the boiler than we've discussed that during our dive planning, we've identified who's going to do the measuring, how we're going to measure, who's going to document the measurements, etc etc.

Not everyone likes diving with other people. If that floats your boat, please fill your boots. Just don't assume teem diving suits everyone.

Same buddy, don't assume every dive is a solo dive just because you're bad at making friends

Every dive is a solo dive whether or not you are diving with others. You are completely responsible for your own safety and must be self sufficient.

BTW what happens when you're separated from teammates/buddies? Do you look around for one minute and ascend?

You follow the standardized missing diver procedures that everyone knows.

 

[Nick_Radov]

Before this descends into a clash of the handbags... The problem with team diving is you're always focussed on the team. If you're relying on them to get you out of the brown stuff, then you have to commit to doing the same for them. This means you're not spending the time you want on the wreck, gawping at fish, taking photos, measuring the boiler, etc.

No that's not an actual problem in practice. Tracking your buddies doesn't require complete focus, you can still take pictures or whatever. Just stay close and look around occasionally. Of course I rely on them to help me get out of trouble, and vice versa.

BTW what happens when you're separated from teammates/buddies? Do you look around for one minute and ascend?

Generally yes, search for about minute and then make a safe ascent to the surface (which might involve some deco stops and deploying an SMB). Depending on the dive site the team might also arrange to meet up at a specific point in case of separation. (I'm talking about ocean diving here. I've heard that the buddy separation protocol is different for cave diving but I don't know about that.)

 

[Wibble]

No I'm relying on a team of people that have similar skills, mindset, and pre-agreed goals many of which are close friends.


Yep we've all committed to taking care of each other and making sure the team succeeds. If the goal of the dive is to measure the boiler than we've discussed that during our dive planning, we've identified who's going to do the measuring, how we're going to measure, who's going to document the measurements, etc etc.


Same buddy, don't assume every dive is a solo dive just because you're bad at making friends


You follow the standardized missing diver procedures that everyone knows.

Sounds awful

It's nice to just enjoy the chatter on the way out; enjoy the dive; then enjoy the chatter on the way back where we all compare how many mermaids we saw, the ship's bell, portholes, tibias, etc.

Generally yes, search for about minute and then make a safe ascent to the surface (which might involve some deco stops and deploying an SMB).

And waste the rest of the dive?

Most of the people I dive with may wave at me as I or they ascend. Spending an hour or more alone decompressing is really calming. Occasionally there's a lazy shot to ascend, so if I only see one strobe flashing, I know I'm last.

 

[Nick_Radov]

The main thing about decompression algorithms is they're statistically configured to get most people out from a dive unbent. There's a degree of additional resilience built in to cope with small variations.

If you dig into the primary research, you'll find that the statistical support for what we're doing is pretty weak. Empirically it seems to work well enough most of the time, but we can't reliably predict effects of minor changes. The algorithms are precise, but are they accurate? Who knows.

In essence this may mean you extend your dive to reduce your GF-high before ascending. For example you might dive with 50:80 normally but choose to extend that to 50:70 to mitigate some additional stress during that dive -- high levels of breathing, etc.

There's no real solid experimental evidence to support that practice, but if it works for you then go for it.