Is it worth it?

[PfcAJ]

Ok, I made a few graphs to show the data.

THERE MIGHT BE A SLIGHT ERROR SOMEWHERE! Its 1am!!

x-axis is #of years certified, y-axis is % of fatalities (n=48).

The top one is a recreation of the graph in the 2009 DAN report. It looks the same.

The bottom one is the same data but instead of multi-year groupings, I took the values and EQUALLY spread them out. So all the 6-10year ones were divided up and have an equal % in each group, I did the same for the 3-5yr group. Why? Because we don't have specifics. Since both middle groupings are so similar, its probably a fair representation of the raw data, but there's probably some variation in real life. For instance, maybe there were 3 fatalities for a diver certified for 5years instead of 2. But the point remains.

Bottom line is that the 1st group is WAY more than the middle ones. The ">10" is so big because it represents 19 divers (48*.4). Since we don't know anything about how long they've been diving other than "greater than 10 years" and that spans such a massive amount of time, I can't really do anything with it.

The moral of the story is that if a diver wants more instructor time they should GO DO IT. That's the 'stay alive' part of the brain telling them what they need to do to stay alive.

No one should shame anyone for seeking more training, no matter how much it seems like just common sense. Not everyone is comfortable and/or experienced in the water or around boats.

 

[Redshift]

The moral of the story is that if a diver wants more instructor time they should GO DO IT. That's the 'stay alive' part of the brain telling them what they need to do to stay alive.

No one should shame anyone for seeking more training, no matter how much it seems like just common sense. Not everyone is comfortable and/or experienced in the water or around boats.

I don't think the general advice given here by those not liking very much the boat diving (and some other specialties) was to not do something a diver wanted to do. It was more of a, if a diver wasn't sure of the need for a certain specialty, then it would be maybe better not to do it. And it was with that spirit that the OP was asking about the specialties. There are some specialties that I wouldn't advise a diver to do just because they exist, without the diver really feeling it's something important. The specific case of boat diving, yes, it's a different experience, but it's something that can be easily done with a more experienced buddy who can provide some guidance. Although that may not be possible for everybody and there are people who are not integrated in a dive group, don't belong to a club, etc and for those then I'd agree that it's better to get some training than to just show up on a boat and get an insta-buddy. In particular if they don't have much experience.

 

[TSandM]

Peter and I have talked about the "boat diving" specialty a lot, as one which is easy to make fun of as being worthless. In fact, if you look at the specialty instructor's manual, there is a LOT of stuff you can teach in the boat diving specialty. You can teach about steering the boat, using the radio, tying knots, docking procedures and other things that might be useful for the student who is either thinking of buying his own boat, or dives off friends' boats. Peter teaches SMB deployment in his boat diving specialty, since the ability to send up a marker is awfully nice when you get blown off the wreck or reef. Different types of entries, and the arrangement of granny lines and deco stations and the like, can be part of boat diving.

The problem with the specialties is the same as the problem with the majority of dive training. They are taught TO THE MINIMUMS to keep cost and time down, and often taught by people who don't have a great deal of experience with the topic they are teaching.

 

[Searcaigh]

Ok, I made a few graphs to show the data.

THERE MIGHT BE A SLIGHT ERROR SOMEWHERE! Its 1am!!

x-axis is #of years certified, y-axis is % of fatalities (n=48).

The top one is a recreation of the graph in the 2009 DAN report. It looks the same.

The bottom one is the same data but instead of multi-year groupings, I took the values and EQUALLY spread them out. So all the 6-10year ones were divided up and have an equal % in each group, I did the same for the 3-5yr group. Why? Because we don't have specifics. Since both middle groupings are so similar, its probably a fair representation of the raw data, but there's probably some variation in real life. For instance, maybe there were 3 fatalities for a diver certified for 5years instead of 2. But the point remains.

Bottom line is that the 1st group is WAY more than the middle ones. The ">10" is so big because it represents 19 divers (48*.4). Since we don't know anything about how long they've been diving other than "greater than 10 years" and that spans such a massive amount of time, I can't really do anything with it.

The moral of the story is that if a diver wants more instructor time they should GO DO IT. That's the 'stay alive' part of the brain telling them what they need to do to stay alive.

No one should shame anyone for seeking more training, no matter how much it seems like just common sense. Not everyone is comfortable and/or experienced in the water or around boats.

How many were wearing split fins?

 

[PfcAJ]

All of them, duh

MOF too.

 

[dmoore19]

It might also include the idea that asking the captain where the life jackets are, what channel on the radio is for emergencies, where is the radio, where is the oxygen, can I see it?

I found out that the boat captain and crew are quite happy to show you these things, in fact if the op is reputable they actually enjoy somebody asking. It made me feel more comfortable.

My boat diving course included all of those things and more

Peter and I have talked about the "boat diving" specialty a lot, as one which is easy to make fun of as being worthless. In fact, if you look at the specialty instructor's manual, there is a LOT of stuff you can teach in the boat diving specialty. You can teach about steering the boat, using the radio, tying knots, docking procedures and other things that might be useful for the student who is either thinking of buying his own boat, or dives off friends' boats. Peter teaches SMB deployment in his boat diving specialty, since the ability to send up a marker is awfully nice when you get blown off the wreck or reef. Different types of entries, and the arrangement of granny lines and deco stations and the like, can be part of boat diving.

The problem with the specialties is the same as the problem with the majority of dive training. They are taught TO THE MINIMUMS to keep cost and time down, and often taught by people who don't have a great deal of experience with the topic they are teaching.

 

[Omisson]

Happy to explain.

>10 years is really open ended and non specific. Think of how ridiculous their graph would have to be if they had a diver at 11 years, 2 at 15, then 1 who had been certified for 30years. What are they going to do? Have 20 "0"s? Silly from a presentation standpoint, so they consolidated.

Lets take a look at your 3rd point for a moment. 35% under two years. 2. Thats it. The next group (under 10, more than 1) is 5 times that. So a bit less than double the % roughly (35% to 60%), but five times the number of years we're looking at. Its not apples to apples.

Back to the 2nd point, if there are more divers certified in the 'mid range' as defined as greater than 2yrs but less than 10yrs, why is that segment so under represented? If all groups were equally likely to experience a fatal accident, we'd see a higher % than 40%. Heck, looking at the divers with <1 and 1 is nearly that value alone, and its a WAY smaller time period.

Its a little late, so I could be off a little here, but I think its fairly clear cut that year for year, the newer a diver is the more likely they are to experience a fatal accident. There's probably some sort of upward trend eventually (complacency factor), but our sample size is just too small to show it. We don't have the data to draw a meaningful conclusion about that.

I hope what I wrote makes sense, and I'll be happy to clarify anything if need be.

The sample size doesn't meet statistical minimums so we are spitballing.

Not to sound nitpicky, but since we can't break-out the < 10 category, and it looks like a 3-5% deviation, these numbers seem statistically equal or at least damn close to the margin of error.

So I don't think your conclusion is accurate.


I think the deaths are spread evenly across the range AND when you take out the unknown causes, and unavoidable a (heart attack, shark attack ) I think all variation they have disappear.

Just my observation as a fully recovered social scientist (archaeology).





Dan-O

Sent from my iPhone using Tapatalk 2

 

[PfcAJ]

Agreed the sample size is pretty darn low and it makes for weak statistics. We COULD go through all the reports and add 'em all up. That would provide strength to the analysis, but someone else can go do that. They all say pretty much the same thing, so it would really just be an exercise to placate certain people.

But just to clarify, you think that the differences between the 1st column and all the others in the 2nd graph is within the margin of error? 30% vs ~3.5% is a BIG jump.

Edit: I just took a look at 6yrs worth of reports, and each one has a remarkably similar trend to the 2009 report. Its not a fluke.

 

[Omisson]

Agreed the sample size is pretty darn low and it makes for weak statistics. We COULD go through all the reports and add 'em all up. That would provide strength to the analysis, but someone else can go do that. They all say pretty much the same thing, so it would really just be an exercise to placate certain people.

But just to clarify, you think that the differences between the 1st column and all the others in the 2nd graph is within the margin of error? 30% vs ~3.5% is a BIG jump.

Glad we Agreed on the first point.

The tallys over say, 10 years may yield statistically significant thresholds but diving science evolved considerably in the period- use of Trimix and Nitrox will skew data in technical and deep recreational ranges. They aren't apple to apple comps. Makes them less of a valid working set.

On the margin of error no- what I'm saying is the breakout differential between :
<2
2-10
>10

Is statistically insignificant and likely within the margin of error using these 3 categories in apportioning death rates.

That's all.




Dan-O

Sent from my iPhone using Tapatalk 2

 

[PfcAJ]

The DAN figures have more than 3 categories though. They have 6. The 1st two (<1 and 1yr) are routinely higher than all the rest except >10.

Furthermore, DAN shows the depth, gas, and cert levels of the reported fatalities. All of these support the notion that its new divers that are more likely to experience a fatal accident.

I'm struggling to see why this is such a shock. Its at least reasonable to expect an inexperienced group as being the group most likely to experience a problem, right?

For the interested reader, here's a link to the DAN papers
https://www.diversalertnetwork.org/medical/report/