Help for Novel

[kaerius]

Deepest dive ever done was to 701 meters, on an experimental gasmix called Hydra10(a hydrogen/helium/oxygen mix with between 1-2% oxygen, hydraheliox becomes explosive in mixes over 4-5%, so it cannot be breathed shallower than 30m due to hypoxia). Note however that it was performed in a diving bell, and I don't think they actually exited to the surrounding sea, but it was done in the mediterranean. Theoretically a mix suitable for 1000m dives could be found, perhaps by adding small amounts of neon and nitrogen to a hydraheliox mix(hydrahelineonitrox? or penta-mix for short?) Note that the decompression necessary to surface(sealevel/1 atmosphere pressure) after such a dive would likely be measured in years.
As with all saturation divebell diving, going shallower than the bell can lead to DCS while still in the water.

Oh and whatever mix you dive at that depth, it's going to be considerably narcotic, and the pressure is going to make breathing quite hard(the gas so much denser), and any exertion could easily become fatal due to the effect of CO2 produced by your body(CO2 is also narcotic at depth).

If you really want an expert opinion, contact the company COMEX, that performed the Hydra10 experiment.

 

[Grenouille]

I don't really understand this need for a gas thing, if there's a structure that keeps the pressure out, that people are inside, and that inside there are trees, plants etc, why do they need a gas other than the regular mix we have on the surface? They're not subject to pressure within the structure, and when they get out, they're in a suit. What's the short explanation for a need to breathe a different gas?

 

[Rich Keller]

As long as the structure and suits are all at one atmosphere (14.7psi) there is no need for for special gas mixes.

---------- Post added May 12th, 2013 at 09:32 AM ----------

The only gas issues you have in your scenario would be keeping the proper balance of gases in a closed environment but this is not going to involve science fiction this would just be off the shelf technology.

 

[Grenouille]

Haha ok well then I think we can close at least that debate!

 

[kaerius]

PS: My gut feeling based on all I know about diving gasses and extreme deep dives, as a layman, is that the biggest hurdle to overcome for anyone contemplating diving at 1km depth, is by far, CO2. Since it's both extremely narcotic(and in a bad way, stoping you from thinking and from seeing), and it is the second of the two big components of breathing, you must get rid of the CO2 your body produces, you may find yourself running into a wall there where the body simply cannot get rid of CO2 fast enough. Any exertion becomes a potentially fatal event, perhaps even swimming, or holding on to a DPV. If I was writing a story in this vein, then the only way to move would be by a DPV attached to the diver, limiting the necessary use of muscles to the outmost. Also I'd probably add a 6th gas to the mix(deuterium, aka heavy hydrogen, the stuff they use for nuclear fusion, expensive stuff!), which would make it a hexa-mix, which also mixes well from a literary standpoint with the old scuba slang for new/complex diving gasses: devil's gas.

 

[gekodivebali]

And the fact that a one atmosphere suit would mean they can ascend to the surface easily, without any deco stops on the way up...

 

[Grenouille]

And the fact that a one atmosphere suit would mean they can ascend to the surface easily, without any deco stops on the way up...

Unless the creator of that place had designed those suits to electronically shut down if they move too far from the shelter, forcing them to stay close

 

[Rich Keller]

Sounds like an underwater prison. The suits used today are self contained so shutting them down at a certain distance would be a problem. If your suit got its air from the habitat via an umbilical then the diver could only go as far as the umbilical could reach.

 

[Grenouille]

Does the umbilical thing feel outdated or could there be an explanation for using that, apart from the keeping them in there thing?

 

[Rich Keller]

Umbilicals are standard equipment for all commercial diving operations, they are by no means outdated.