Free SSI Science of Diving Specialty

[tursiops]

but only covered SAC and not RMV

What is the difference in these, to you? Everybody seems to have their private definitions....

 

[loosenit2]

What is the difference in these, to you? Everybody seems to have their private definitions....

true that they are poorly defined writ large and they are used differently by different agencies and instructors

if not answering a question for a specific agency I tend use the definitions that SAC is consumption normalized to 1ATA expressed either in psi/min or volume/time. RMV is the air consumption at a specified depth, always expressed as volume over time (ie .45 cu/ft per min).

 

[Angelo Farina]

Sorry, no: this is only true because you never reach the max depth that you planned for. You never absorbed your planned amount of nitrogen and that's why it's "safe". If you follow this ad absurdum, you'll arrive at a very safe dive plan for a "craziest" profile with bottom time of 0 minutes.

You can emulate this with a computer by turning its safety factor to 11. Dive a GF 1/1 and you'll be just fine. (In principle: not that a real life computer would let you go quite that far.)

I did never talk of anything "planned". When for any reason, I do not think that the deco calculated by the computer is reliable, I fold back to using the tables with the max effective depth reached (it does not matter for how much time) and the total diving time (from the "splash" to the moment I reach 9 meters). I know, it is very conservative and forces to a long deco, but it is safe.
I repeat, I do this just when I cannot thrust the computer anymore (or when the computer fails). In "normal" cases the computer is just fine, no need to tweak it changing the standard settings.

 

[Angelo Farina]

It is not just about N2 uptake/offgas. It is also about ascent rates....at least the computer tries to monitor this and take it into account, the tables do not. And your zig-zag profile has a lot of ignored ascent rates if you are on tables.

Tables were assuming an ascent rate of 18 meters/minute, which surely I never exceeded...

 

[dmaziuk]

I repeat, I do this just when I cannot thrust the computer anymore (or when the computer fails). In "normal" cases the computer is just fine, no need to tweak it changing the standard settings.

I get that, your assertion is you can't trust the computer on "crazy" (by extension, any non-square) profiles. Mine is that after some 112 years of development and use, the model inside is more trustworthy than the alternatives. Sane profiles or not.

PS keep in mind that tables are using the same model, you're just upping the conservatism by lying to it: exaggerating your actual depth. So in effect you don't trust it to give the right answers for the right numbers, but you do trust its answers for the wrong numbers.

 

[tursiops]

But...if you go slower than that, you are spending more time at depth, thus ongassing more, than the tables are accounting for.

 

[TMHeimer]

Click Programs & Cards > Programs > Science of Diving on a desktop machine.

Or on mobile click Programs & Cards > Courses > Science and Diving

Tables are located at Programs & Cards > Tables on your mobile device.

I did the top line instruction you sent on my laptop. What do I click on when I get to Science and Diving? I don't know how to get the course started. You have to be patient with me as I am a computer idiot. Assume I have no idea what to do or if I should do anything with the top tool bar, etc.

Thanks.

 

[BlueTrin]

I did the top line instruction you sent on my laptop. What do I click on when I get to Science and Diving? I don't know how to get the course started. You have to be patient with me as I am a computer idiot. Assume I have no idea what to do or if I should do anything with the top tool bar, etc.

Thanks.

I did the following:
- log in on https://my.divessi.com/myssi
- top left menu (3 bars) then find and select “programs” under “programs and cards”
- you should see “science of diving” somewhere if you scroll down, just click go to first page

If you have a smartphone, I find that the smartphone version is much easier to use.

 

[TMHeimer]

I did the following:
- log in on https://my.divessi.com/myssi
- top left menu (3 bars) then find and select “programs” under “programs and cards”
- you should see “science of diving” somewhere if you scroll down, just click go to first page

If you have a smartphone, I find that the smartphone version is much easier to use.

Did that. Clicked on "View first page". Only a picture of a diver's head comes up. Clicked on the other thing-- like, view last page viewed or something-- SSI course descriptions comes up. Nothing else to click on. Have no smart phone (well, I do, but don't pay for it to be smart).

 

[Sean Walberg]

I did the following:
- log in on https://my.divessi.com/myssi
- top left menu (3 bars) then find and select “programs” under “programs and cards”
- you should see “science of diving” somewhere if you scroll down, just click go to first page

Were you already signed up with SSI? I signed up this morning and all I see is some intro courses. SSI's website lists OW as a pre-requisite for this course, and since I didn't do my OW through SSI they've got no idea who I am.

I emailed my local SSI dive shop and he told me to sign up on the website and call in on Monday, so maybe they have to do something for people that aren't known by the system.