is Sidemount diving more safe?

[Rilelen]

as main data keeper for me data- its all rubbish and waste of ressources but i thought maybe one had the spirit and enthusiasm to drag them together and make funny columns or checkered lines

I *am* a research statistician, with an expertise in experimental design. SlugLife is correct here; as multiple folks have pointed out, there's not a sufficient sample size to draw any reasonable conclusions, and the list of potential confounds is so long that even if you were to find an effect, it could be due to any number of causes - some of which we can measure and (partially) control for, and some of which we can't.

The only real way to know would be to assemble a very very large group (you'd need a huge sample given the low baserate of deaths/incidents) of divers trained in both SM and BM, who would be willing to be randomly assigned by a researcher to do their dives in SM vs BM for a given stretch of time. (You could also randomly assign per dive, which would increase statistical power, but also add enormous logistical complexity). Then see whether more of the divers in the BM condition have accidents/incidents than those in the SM condition. I highly doubt any ethics board would even approve that study (i.e., could end up randomly assigning someone to dive a SM-only cave in BM), and even if they did, there's almost certainly not any way to get the sample size/level of compliance you'd need for causal inference.

Some questions are just not very amenable to being answered empirically; a similar problem exists (for example) for whether any level of diving is safe during pregnancy. The number of women diving while pregnant is so low, and complications rare enough, that the published literature has more or less concluded that it's unlikely we will ever have the sample size to allow us to statistically determine the risk (and whether any safe limits exist). The best we can do is draw on animal studies, and our theoretical knowledge of physiology and how diving could affect that in pregnancy. The same approach is the best that can be taken here; there may be theoretical arguments for SM vs BM, but it's unlikely we'll ever have sufficient data to test those arguments empirically.

And, as I like to tell my students: the plural of anecdote is not "data".

 

[lowwall]

And, as I like to tell my students: the plural of anecdote is not "data".

You had me nodding my head right up to this. But the original quote was "The plural of anecdote is data." (see below)

I understand why the "not data" version appeared. The word "anecdote" certainly suggests the datum was not collected in a way that would be amenable to statistical analysis. But statistical analysis is not the only method for analyzing data. Especially in the messy world of human activity.

This very forum is an example of this. No one is trying to aggregate the information here, instead we look case by case to see if there's anything we should change in response to situations we hadn't previously considered.

Another example, after I started diving I wanted to get an idea of the inherent dangers in the sport. I found one of DAN's reports that gave a brief synopsis of all the diving fatalities the previous year and began reading it. It soon became clear that only a handful of types covered the vast majority of deaths: diving beyond your certification level, especially in overhead environments; diving with known defective gear; diving with known major health issues. No statistics were needed for me to conclude that avoiding these things is the basis for a long and happy diving career.

The Plural of Anecdote is Data – Quote Investigator®

quoteinvestigator.com

 

[Stunni]

this suggests that there are some divers out there who go diving without thinking what they do?
is there a statistic how to recognize them?

You had me nodding my head right up to this. But the original quote was "The plural of anecdote is data." (see below)

I understand why the "not data" version appeared. The word "anecdote" certainly suggests the datum was not collected in a way that would be amenable to statistical analysis. But statistical analysis is not the only method for analyzing data. Especially in the messy world of human activity.

This very forum is an example of this. No one is trying to aggregate the information here, instead we look case by case to see if there's anything we should change in response to situations we hadn't previously considered.

Another example, after I started diving I wanted to get an idea of the inherent dangers in the sport. I found one of DAN's reports that gave a brief synopsis of all the diving fatalities the previous year and began reading it. It soon became clear that only a handful of types covered the vast majority of deaths: diving beyond your certification level, especially in overhead environments; diving with known defective gear; diving with known major health issues. No statistics were needed for me to conclude that avoiding these things is the basis for a long and happy diving career.

The Plural of Anecdote is Data – Quote Investigator®

quoteinvestigator.com

 

[lowwall]

this suggests that there are some divers out there who go diving without thinking what they do?
is there a statistic how to recognize them?

Dangling octo and selfie stick.

 

[Stunni]

do you know where to buy this special cam bands that can stick on the sphere of the tank neck?

 

[Marie13]

do you know where to buy this special cam bands that can stick on the sphere of the tank neck?

Huh?

 

[Stunni]

like this one... found on PADI homepage must be some extraordinary high end sticky cordura belt...
sorry, my kind of humor. barely on the cylindric shape...
its another visual indicator like @lowwall mentioned

awful. simply enter "shore dive" google picture search

How to Make a Perfect Shore Entry for Scuba Diving

Want to learn how to make shore-diving entries easier? Here are our tips and tricks to perfect your shore-diving techniques.

www.sportdiver.com

sorry, think this Fred goes offside...

 

[SlugLife]

as main data keeper for me data- its all rubbish and waste of ressources but i thought maybe one had the spirit and enthusiasm to drag them together and make funny columns or checkered lines

Such an effort would be much more than an Eve Online spreadsheet.

Alternatively, 87% of statistics are simply made up, so you could just go that route.

The only real way to know would be to assemble a very very large group (you'd need a huge sample given the low baserate of deaths/incidents) of divers trained in both SM and BM, who would be willing to be randomly assigned by a researcher to do their dives in SM vs BM for a given stretch of time.

Right, even if we had 1000 divers participate, they'd want compensation (I would anyway), and we'd be (un)lucky to have one death, and the cause might be "ate Taco Bell before cave-diving, and had catastrophic rear 2nd stage failure."

 

[Rilelen]

This very forum is an example of this. No one is trying to aggregate the information here, instead we look case by case to see if there's anything we should change in response to situations we hadn't previously considered.

You're totally right that the modified quote pulls from an original that argues the opposite; that said, the modified version makes sense in the context I'm usually teaching (i.e., quantitative data analysis), and is pretty widespread at this point. Esp when you have students who like to "counter" mountains of statistical evidence with "But I know a man who...".

That is not to say (and I would totally agree) that quantitative data analysis is the only way to gain insight or knowledge about the world! That's really a fun philosophy of science question. I have fantastic colleagues whose primary focus is qualitative methods who would vehemently agree with you. For my own part, I see qualitative data/anecdata as invaluable for exploratory data analysis and formulating research hypotheses; strong causal inference usually (although not always - see Popper's black swan) tends to require more quantitative approaches. But I also come from a strong positivist tradition, and that approach isn't shared by everyone (which is great, the world would be a more boring place if we all thought alike).

And, even with all that...I still totally agree that there are simply some questions - like SM vs BM, diving while pregnant, etc - we just can't answer empirically, and where it doesn't make sense to try.

 

[DiveLikeAMuppet]

What risks are you trying to mitigate?

Getting stuck in a restriction or a broken manifold? Sidemount helps.

Preventing broken bones before jumping off a rocking boat? Backmount wins, no contest.

What level of training? Sidemount requires more training and tweaking - we had to put a diver on O2, as he skipped 10 mines of deco after he was not able to dump gas from his sidemount wing due to its construction/his trim. I haven’t seen that happen with backmount.