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strattST
23-03-2015, 02:42 PM
Hi guys,

Not sure if this is the right place to post this question but here goes...

Been reading up a bit on saturation diving and theres one question i cannot find the answer to no matter where i look.

How can you calculate the point you become saturated? as in if you dove to 90m how long would you have to be down there before you became saturated?

Is there a standard calculation or set of equations to try and predict this?

Cheers,
Chris

notdeadyet
23-03-2015, 03:04 PM
It would be the point at which more bottom time makes little or no difference to deco time. Not necessarily at the depth of the dive, divers would likely be pressurised at a shallower storage depth and be transferred under pressure to the excursion ie working depth.

jb2cool
23-03-2015, 03:25 PM
I think a tissue can be thought of as saturated after 6 half times, this is really 98.43% saturated but probably near enough. Tissue half times vary from 1 minute to 720 minutes so the 1 min half time tissue will be saturated in 6 mins but the 720 minute tissue will need 72 hours (3 days) to become fully saturated.

Some info here (I know it's Wikipedia so take with a small pinch of salt)
http://en.wikipedia.org/wiki/Decompression_theory

And even a nice graphic here
http://commons.wikimedia.org/wiki/File:Buhlmann_ZH16a_half_times_and_saturation_time s.svg#/media/File:Buhlmann_ZH16a_half_times_and_saturation_time s.svg

MikeF
23-03-2015, 03:59 PM
oi, dived not dove, we'll have no americanisms here.

gobfish1
24-03-2015, 01:02 AM
http://www.dtic.mil/dtic/tr/fulltext/u2/a227673.pdf

John_ZA
07-06-2015, 08:49 PM
oi, dived not dove, we'll have no americanisms here.

Thanks

heliumthief
25-06-2015, 04:43 PM
In practice, Saturation is just based on the depth/bottom time of the particular tables used by the company. ie. if you were getting blown in to 60' and the company was using USN tables, then you could still be recovered without decompression up to the 60min bottom time at a 30ft/sec ascent rate. But this would only ever be used if a diver became unwell on blowdown etc.

If you are going to a deeper storage depth, then the point at which you could abort would be calculated by the LSS, but it would be a matter of minutes, so generally the divers should be considered to be committed very quickly.

jturner
26-06-2015, 08:15 AM
In practice, Saturation is just based on the depth/bottom time of the particular tables used by the company. ie. if you were getting blown in to 60' and the company was using USN tables, then you could still be recovered without decompression up to the 60min bottom time at a 30ft/sec ascent rate.

30ft/sec?! Hardcore indeed!!! ;-)

heliumthief
26-06-2015, 10:17 AM
Minute!

Foggy
26-06-2015, 02:29 PM
Don't forget that different tissues reach saturation at different times...

You could liken it to a Top Gear drag race between a ferrari and a Gwizz. The ferrari (fast tissue) is going to get there first...

But to answer the OP's fundemental question "what is the point of saturation", I can't see that it has any point other than to stop poeple hogging all the gas. Unless of course you sell dive software or dive computers or helimum..;)

If anyone reading this thinks there's an ounce of reason in this post...think again.
For forum officiandos....its friday :)

heliumthief
26-06-2015, 10:49 PM
...so to distil the facts, the point of Saturation is to make enough money for two houses, a Porsche and a range rover for the missus, before giving them all to the tax man!.......so...what IS the point?!

MikeF
26-06-2015, 11:15 PM
The point of saturation is to keep all the divers quarantined in a small tin can so the rest of the crew can live in civilised envionment without loads of divers loafing around the rec room farting, scratching their balls and scoffing all the bacon rolls.

heliumthief
27-06-2015, 12:01 AM
...which is the preserve of the Conversion Engineers!
Seriously, I've never seen a disrespected discipline like divers on a diving vessel! Even when we had a serious incident, and when we got out, crew were coming up to us with tears in their eyes ' you guys deserve everything..' Etc. etc...6 months later, it's 'fucking divers..' All over again!
..lucky no diver cares what anyone else thinks, eh?!