Disturbing trend in diving?

[Leatherboot69]

Comparing DSD mortality rates with that of recreational divers in general is not a valid analysis and would not support a conclusion that "relying on an instructor or DM to keep one out of trouble is cool."

Conditions for diving under the DSD program are vastly different from those that an OW diver would see and accomplish. In the DSD program, a diver-a scuba diver-is under the direct supervision of a dive professional at all times, with a very low diver-to-professional ratio, in very close contact distances. The professional is assumed to have total responsibility and control of the dive parameters. The OW recreational diver is understood to understand and have demonstrated sufficient level of skill to function independently and autonomously, ie - the ability to be responsible for their own safety (although, I doubt some could count the number of tanks on their back and get the same number twice-in-a-row). The dataset, if one includes all "recreational divers" includes folks with varying levels of supervision from loosely following a dive guide to zero professional supervision. The times I've been with groups as described in the OP's first observation, those included 6-10 folks following a DM, at distances from contact to 100+ ft laterally at depths ranging probably +/- 20 ft from the DM (sometimes I've been known to be 40 ft below as I was logging deep experience required towards future, higher-level tech cert at depths I cannot reach in local lakes).

Also, the time of exposure varies from DSD program divers - limited to only a few hours of very closely supervised dive activity under likely pretty good conditions to a lifetime of diving experience (days, weeks, months, maybe years underwater) in all sorts of conditions - temperature, visibility, currents, depths, overhead environments, night, varying equipment, etc.

Kinda like comparing driving a governed go-cart around a bumpered track at the local putt-putt golf-and-go-cart entertainment center to throwing somebody into day-to-day Houston traffic and comparing fatal accidents over time.

But fewer people die doing one than the other, amirite?

 

[John C. Ratliff]

Leatherboot69:
I’ve only read the abstracts so I know I’d need to scrutinise the methodologies to make them empirically comparable, but the following sources indicate that DSD fatalities are 0.87 per 100,000 participants, compared to 2 per 100,000 participants for recreational scuba diving more generally.

Comparing DSD mortality rates with that of recreational divers in general is not a valid analysis and would not support a conclusion that "relying on an instructor or DM to keep one out of trouble is cool."

Conditions for diving under the DSD program are vastly different from those that an OW diver would see and accomplish. In the DSD program, a diver-a scuba diver-is under the direct supervision of a dive professional at all times, with a very low diver-to-professional ratio, in very close contact distances. The professional is assumed to have total responsibility and control of the dive parameters. The OW recreational diver is understood to understand and have demonstrated sufficient level of skill to function independently and autonomously, ie - the ability to be responsible for their own safety (although, I doubt some could count the number of tanks on their back and get the same number twice-in-a-row). The dataset, if one includes all "recreational divers" includes folks with varying levels of supervision from loosely following a dive guide to zero professional supervision. The times I've been with groups as described in the OP's first observation, those included 6-10 folks following a DM, at distances from contact to 100+ ft laterally at depths ranging probably +/- 20 ft from the DM (sometimes I've been known to be 40 ft below as I was logging deep experience required towards future, higher-level tech cert at depths I cannot reach in local lakes).

Also, the time of exposure varies from DSD program divers - limited to only a few hours of very closely supervised dive activity under likely pretty good conditions to a lifetime of diving experience (days, weeks, months, maybe years underwater) in all sorts of conditions - temperature, visibility, currents, depths, overhead environments, night, varying equipment, etc.

Kinda like comparing driving a governed go-cart around a bumpered track at the local putt-putt golf-and-go-cart entertainment center to throwing somebody into day-to-day Houston traffic and comparing fatal accidents over time.

There is one other aspect not shown here, and that is that the numbers included in their data are vastly different, and probably don't support normalizing to #/100,000.

SeaRat

 

[OMyMyOHellYes]

But fewer people die doing one than the other, amirite?

But without correlation, what's the point?

Maybe we should take into account the number of folks that die on the crapper.

(At the risk of incurring the wrath of a certain segment of DC politics, there's this from the NIH ... )

Cardiac arrest in the toilet: clinical characteristics and resuscitation profiles - PMC

The great majority of non-traumatic cardiac arrests (CA) occur at home. The toilet is a closed and private room where CA occurs frequently. However, due to the feelings of privacy that are associated with this room, the circumstances and causes of ...

pmc.ncbi.nlm.nih.gov

 

[John C. Ratliff]

I thought I'd show you one of my dive debriefing sheets I filled out on August 11, 1977. I was testing my Nemrod Snark III regulator, that I had overpressure relief valve newly cleaned and repaired. I noted several small problems which did not affect the overall performance of the regulator.

SeaRat

 

[TMHeimer]

Comparing DSD mortality rates with that of recreational divers in general is not a valid analysis and would not support a conclusion that "relying on an instructor or DM to keep one out of trouble is cool."

Conditions for diving under the DSD program are vastly different from those that an OW diver would see and accomplish. In the DSD program, a diver-a scuba diver-is under the direct supervision of a dive professional at all times, with a very low diver-to-professional ratio, in very close contact distances. The professional is assumed to have total responsibility and control of the dive parameters. The OW recreational diver is understood to understand and have demonstrated sufficient level of skill to function independently and autonomously, ie - the ability to be responsible for their own safety (although, I doubt some could count the number of tanks on their back and get the same number twice-in-a-row). The dataset, if one includes all "recreational divers" includes folks with varying levels of supervision from loosely following a dive guide to zero professional supervision. The times I've been with groups as described in the OP's first observation, those included 6-10 folks following a DM, at distances from contact to 100+ ft laterally at depths ranging probably +/- 20 ft from the DM (sometimes I've been known to be 40 ft below as I was logging deep experience required towards future, higher-level tech cert at depths I cannot reach in local lakes).

Also, the time of exposure varies from DSD program divers - limited to only a few hours of very closely supervised dive activity under likely pretty good conditions to a lifetime of diving experience (days, weeks, months, maybe years underwater) in all sorts of conditions - temperature, visibility, currents, depths, overhead environments, night, varying equipment, etc.

Kinda like comparing driving a governed go-cart around a bumpered track at the local putt-putt golf-and-go-cart entertainment center to throwing somebody into day-to-day Houston traffic and comparing fatal accidents over time.

Yes. I didn't take a DSD myself, nor did I ever teach it. My problem with it is two fold. One is that I've heard stories of the instructor (or DM) to student ratios being dangerously ignored. The other is the ratios themselves. If the instructor has only two students and one panics and bolts to the surface he/she will be leaving one of the two not directly supervised. And at the limit of 4 students to one instructor, you can multiply that problem. I don't think it is even possible for one instructor to always be within grabbing distance of two students at all times, much less four students.

 

[Cthippo]

Yes. I didn't take a DSD myself, nor did I ever teach it. My problem with it is two fold. One is that I've heard stories of the instructor (or DM) to student ratios being dangerously ignored. The other is the ratios themselves. If the instructor has only two students and one panics and bolts to the surface he/she will be leaving one of the two not directly supervised. And at the limit of 4 students to one instructor, you can multiply that problem. I don't think it is even possible for one instructor to always be within grabbing distance of two students at all times, much less four students.

How is that different in an OW class?

 

[The Chairman]

Yes. I didn't take a DSD myself, nor did I ever teach it.

I've taught a dozen or more, and the biggest hurdle, as with most divers is mask clearing. In the 2 to 3 hours I have them in the pool in the am, they learn trim, buoyancy, mask clearing, and reg retrieval on a long hose. One time we passed a typical class all kneeling in a circle on the reef. After the dive, I was questioned by the student why I was so strident about not touching the reef. Yeeesh!

If the instructor has only two students and one panics and bolts to the surface he/she will be leaving one of the two not directly supervised. And at the limit of 4 students to one instructor, you can multiply that problem.

Since I committed to no kneeling in the pool or OW, I have yet to have a student bolt to the surface. Teach them control from the beginning and they have no need to panic. It's really not that difficult to do. Instructors often create the monsters y'all complain about.

 

[Leatherboot69]

I did a DSD as a customer in 2022 and have subsequently led them as a DM (noting my choice of language, as they are ‘experiences’ rather than ‘training’)

You do have to do a pool or confined water dive before you are allowed to do an Open Water dive. My confined water dive started kneeling in chest deep water and subsequently went no deeper than 5 metres, with one DM for two of us. Easy peasy. I didn’t go onto do a DSD OW dive as a customer. But this requirement is presumably to check that people are comfortable underwater before doing a limited open water dive.

But even accepting the argument that the two sources don’t allow one to compare DSD to OW dives (which I don’t), you haven’t actually provided any evidence to support the premise that DSDs are more dangerous. If this is an important part of your argument, let’s see the source. #changemymind

 

[Leatherboot69]

Yes. I didn't take a DSD myself, nor did I ever teach it. My problem with it is two fold. One is that I've heard stories of the instructor (or DM) to student ratios being dangerously ignored. The other is the ratios themselves. If the instructor has only two students and one panics and bolts to the surface he/she will be leaving one of the two not directly supervised. And at the limit of 4 students to one instructor, you can multiply that problem. I don't think it is even possible for one instructor to always be within grabbing distance of two students at all times, much less four students.

If one diver bolts to the surface, they’ve gone to safety. Head up slowly with the other divers. I’ve had a similar scenario when DMing an OW course

Also the ratios allow instructors/DMs to dive with 2/4 divers. It doesn’t mean they need to - it’s up to their professional judgment to manage the group and dive based on the conditions they encounter. That’s why they’re professionals.

 

[The Chairman]

no one has yet provided any evidence that DSDs are more dangerous.

It's not the class: it's the instructor. It's actually the style of the instructor. Students who have trim/buoyancy thrown at them at the very end of the class will conduct their dive in panic or just shy of it. They've been sold the lie that it will take 100 dives to learn buoyancy, and they are scared of hurting themselves. Rightly so.

Kneeling has been a part of dive instruction as far back as I can remember. It's how I first learned, how I was finally certified, and then it became a part of my NAUI ITC. Having students planted firmly on the bottom gives the instructor a modicum (illusion?) of control, but it denies the student truly learning buoyancy and self-control for themselves.

It's why we lose so many divers. They get certified and then have the crap scared out of them on their first dive without an instructor. It's why so many students feel a need to go from one class to another. Having an instructor around to pull their butts out of the abyss if they make a big mistake. They lack control. They lack competency.

Twenty or thirty years ago, it was rare to see non-fit people diving. I saw one class doing pushups in full kit, mask, wetsuit, and duck fins included. You had to be because we learned on our knees back then too. Contrary to the rose colored glasses worn by many old-timers, our collective buoyancy was crap. We had no problem crawling on the reefs. I bought jet fins partly because the Scuba God who sold them to me told me I could kick the crap out of the reef, but not hurt the fins.

/rant