Free SSI Science of Diving Specialty

[Manatee Diver]

Well I went through it, and by went through it I meant I just skimmed it. The hardest part of the entire course was the final exam questions that required the SSI dive tables. Everything else was pretty basic to me.

Not bad definitely more in depth than other recreational courses I've taken. But well short (and that is to be expected) of a tech course or Deco for Divers.

 

[Sloeber]

Just want to add a quick update on this. Although I read (and typed here) the program started on April 12, it didn't click with me that April 12 wasn't until Sunday. I guess I lost track of the days, not sure how that could happen lately. So, ahhh, oops on my part I guess? Hopefully SSI doesn't charge me for all these classes I've given out today hahahaha. Anyways, feel free to send me your contacts but from this moment moving forward I'll hold off on unlocking your class until Sunday afternoon. Thanks!

 

[TMHeimer]

Just want to add a quick update on this. Although I read (and typed here) the program started on April 12, it didn't click with me that April 12 wasn't until Sunday. I guess I lost track of the days, not sure how that could happen lately. So, ahhh, oops on my part I guess? Hopefully SSI doesn't charge me for all these classes I've given out today hahahaha. Anyways, feel free to send me your contacts but from this moment moving forward I'll hold off on unlocking your class until Sunday afternoon. Thanks!

My class has been unlocked and I'm registered now with SSI. Can't find where to click on "My Training" in the tool bar. Maybe it's not there yet because it's not April 12 yet?
Also, are the SSI tables provided in the course (I have none)?

 

[saxman242]

Also, are the SSI tables provided in the course (I have none)?

They're available in the SSI app or you can find them online

 

[TMHeimer]

They're available in the SSI app or you can find them online

Thanks.

 

[EFX]

That bit did stand out to me as being misleading. I wonder if it was written a while ago in the early days of computers. I can forgive the overly simplistic coverage of decompression theory. This definitely isn't meant a deco manual.

The copyright on the book I have is 2010, definitely after the early days of computers. The minimum age for taking this class is 10 years according to SSI's facts on the course. I think the misleading statements and errors creep in when trying to make a complicated [decompression] theory simple enough for 10 year olds. With a young audience in mind, overall the section on decompression theory is good but I think SSI should do a rewrite. Consider this paragraph called Dive Computers from page 3-16 and 3-17:

"Dive computers were designed for multi-level diving and are an excellent tool if they are used properly and conservatively." [ssi] Yes, good. [efx]

"Use the computer with deep-to-shallow profiles, not deep-shallow-deep profiles." [ssi] The recommendation to not do sawtooth profiles is outdated but for novice divers is good advice. [efx]

"The computer continuously computes nitrogen absorption based on the actual depth and time actually spent there." [ssi] Ok, good. No argument there. [efx]

"Therefore, if divers go deep then shallow, their nitrogen absorption is computed at a slower rate at the shallow depth." [ssi] Misleading, but without explaining tissue compartments and half-times it is forgivable. [efx]

"However, on descending again to greater depths, the theoretical nitrogen absorption is increased accordingly." [ssi] Yup. Nothing wrong with that. [efx]

"As indicated earlier, the residual nitrogen affects that process, yet the computer does not accurately account for this effect." [ssi] This is where the author went off to never-never land. The main advantage for using a computer for multi-level diving is to do just that -- track residual nitrogen at varying depths. [efx]

"Therefore, the computer is not calculating absorption the same way your body is, which is potentially hazardous." [ssi] With this statement the author clicked their heels three times and came back to earth. If this was the whole point of the paragraph then the author is dead-nuts on. Decompression models do not tell us exactly what happens inside the body but this last point could have been said separately apart from the comments on tissue absorption. [efx]

Take the course and get the book. [efx]

 

[Manatee Diver]

@EFX The current computer section of the Science of Diving is a bit better, there are some things I disagree with, like the idea that computers aren't advantageous for task oriented divers or square dive profiles; or that reverse profiles are something they aren't programmed for. But overall I think it does adequately explain the benefits and risks of dive computers.

 

[saxman242]

@EFX The current computer section of the Science of Diving is a bit better, there are some things I disagree with, like the idea that computers aren't advantageous for task oriented divers or square dive profiles; or that reverse profiles are something they aren't programmed for. But overall I think it does adequately explain the benefits and risks of dive computers.

It does still make the same statement about nitrogen loading when going from shallow to deep though.

I, unfortunately, don't have enough knowledge of exactly how things are calculated to technically refute it, although it goes against my understanding. It wouldn't, however, shock me if the very early computers did calculate in that way when going shallow to deep and that it's just a very dated statement. I would like to see that part updated.

 

[Angelo Farina]

It does still make the same statement about nitrogen loading when going from shallow to deep though.

I, unfortunately, don't have enough knowledge of exactly how things are calculated to technically refute it, although it goes against my understanding. It wouldn't, however, shock me if the very early computers did calculate in that way when going shallow to deep and that it's just a very dated statement. I would like to see that part updated.

My understanding is that all these algorithms are just a quite coarse, oversimplified model of what happens inside your body while diving. These algorithms have been verified to be reasonably safe when diving some standard profiles.
When you dive a completely crazy profile, there is no certainty that the algorithm will correspond accurately to what's happening in your body. No one knows what's happening really.
Thrusting an algorithm too much, when used in unexplored territory, is something I definitely do not endorse.
I work with computer models every day, as I am a scientist and an engineer. I actually wrote computer programs employing advanced simulation algorithms. And exactly for this I do not thrust them too much...
So I find that these SSI warnings should be taken seriously, and discarding them as "errors", or "those guys do not understand how a modern computer works" is not a satisfying way of criticising these online lessons. They appear prudent to me, and prudent is OK.

 

[formernuke]

My understanding is that all these algorithms are just a quite coarse, oversimplified model of what happens inside your body while diving. These algorithms have been verified to be reasonably safe when diving some standard profiles.
When you dive a completely crazy profile, there is no certainty that the algorithm will correspond accurately to what's happening in your body. No one knows what's happening really.
Thrusting an algorithm too much, when used in unexplored territory, is something I definitely do not endorse.
I work with computer models every day, as I am a scientist and an engineer. I actually wrote computer programs employing advanced simulation algorithms. And exactly for this I do not thrust them too much...
So I find that these SSI warnings should be taken seriously, and discarding them as "errors", or "those guys do not understand how a modern computer works" is not a satisfying way of criticising these online lessons. They appear prudent to me, and prudent is OK.

I'm wondering if this is just because we really don't know much about what DCS is caused by. Granted I'm not in nor have I ever been in the medical field. But everything I've read in relation to diving DCS is based on young fit navy guys back in the day and even then since every person is different those results were still not conclusive. So we have raw data that is of semi-questionable accuracy and we are trying to write computer programs to calculate what we don't know.

Am I saying that tables are better than computers, no. I will say that because you can only do square (not mulit level) profiles with tables so they are more conservative.