Help for Novel

[kaerius]

Make it less than 500m then existing tech can cope. Mind you unless their suits are hard-shell, the decompression times would still be measured in weeks/months at 500m(say about 3 months on hydraheliox for saturation diving). Many of the same obstacles remain for hard-shell suits, but the material strength requirement and buoyancy bladder size are halved.

Around less than 200m and escape to the surface with scuba gear may be possible with enough tanks, decompression being days rather than months or years.

---------- Post added May 12th, 2013 at 03:33 PM ----------

Right. We need to get rid of the air.

Well, doing the Abyss thing would cut down on required suit strength, they could basically do it in modified spacesuits since there's no compressible gas... true dat.

 

[Grenouille]

Shallower it'll be, then. Anyone knows where I can find a map of how deep different parts of the ocean are? Especially the area around Miami.

 

[RJP]

Shallower it'll be, then. Anyone knows where I can find a map of how deep different parts of the ocean are? Especially the area around Miami.

Click here:

Let me google that for you

 

[Grenouille]

Arf... I pass for the idiot who doesn't know Google exists. I did try to research it before but didn't get to what I was trying to find, I thought you'd have something clearer than what I'd seen. Thanks for the link.

 

[PeterNBiddle]

Oh and liquids don't become denser with pressure, liquids are incompressible, well, right up until the point where they become solids(like the metallic hydrogen on the surfaces of gas giants).

What about dilatant fluids? Maybe not denser exactly, but certainly an increase in shear viscosity, which could have some bearing here.

 

[kaerius]

What about dilatant fluids? Maybe not denser exactly, but certainly an increase in shear viscosity, which could have some bearing here.

Well they would still not compress under pressure, only have altered properties. And they would still do essentially nothing for protecting against pressure unless you fill the airspaces in the suit and diver's body with them, which obviously wouldn't really be all that beneficial. They'd just tighten around the airspace like any other liquid. Pressure protection needs to be rigid to work, which means solids.

 

[gekodivebali]

I think you got 2 options froggy:

1) limit depth to 100-200m & use regular, ambient pressure systems. Access to the surface is made almost impossible by the decompression requirements. It would take weeks to safely ascend to the surface from saturation at 100m and would be impossible without surface support. You still need to deal with what gases to mix in order to limit O2 exposure, narcosis and HPNS at depth. The method of obtaining (drilling into gas forages for helium, O2 from water, etc) the necessary gases also needs addressing. However, this is within the realm of possibilities with today's tech and not scifi anymore.
This means your characters can use a regular dry suit at depth for several hours at a time. They gain in flexibility and can do a lot more things on excursions outside the base. A lot more life to encounter at these depths too...
This would make for nice side plots. One could try to surface and suffer/die from DCS. One could experience problems with rebreather and end up with CO2 hits or O2 toxicity. Tethered umbilicals could be used besides SCUBA for specific missions.

2) keep depth between 500m-1km. This pretty much limits to 1 atmosphere suits. Much easier to deal with in terms of gases. Big disadvantage is that they are much more cumbersome, do not look good at all and could allow an ascent to the surface without decompression obligations...

Number 1 is a lot more sexy if there are no imperatives to be deeper for the sake of the plot.

 

[Grenouille]

Well, for the plot, I need them to not be able to go back up just with their suit, but to be okay going back on a submarine and take 3 days to decompress in there before emerging, if that makes sense at all (forcing the crew to stay together in there for 3 days). I'd like them to build a probe that they send to the surface to get some data, and I'd like them to try and build a capsule big enough for 2 people, with material from mostly plane wrecks, for someone to go back up (at a time when they don't have a submarine yet), but that plan fails and leaves one of them paralyzed after a decompression accident, and another dead. I really would like to use the umbilical cord, I find that awesome. The only thing is the guy who designed it didn't want them to go back up for a long time, and I feel like 100 or 200 meters wouldn't be a good guarantee for that, it doesn't feel "that deep" for such a project.

 

[ektess1]

Put your habitat at a depth too deep for humans to live breathing any gas at that pressure. Have the habitat pressurized to the maximum depth that humans could live with a special mystery breathing gas. Base the gas on current science, add a dash of fiction, mention it once, and be done with it. The gas is not important unless you are trying to make this science instead of science fiction.
With the habitat pressurized they would need to decompress to reach the surface. This would allow you to bend your heroin and trap the people in the habitat. Because the structure and special suits are pressurized they would not need to be as strongly constructed. The suit could be tethered because they need the habitat to maintain the suits gas pressure and volume.
Science fiction needs to be plausible. It does not need to be attainable. That would make it science.

 

[Griffo]

Just invent some experimental drug that stops the blood from absorbing any gasses via diffusion. You'd still get O2 from it bonding with Hemoglobin, your body would slowly offgas everything else, and all your problems with narcosis, decompression etc would magically go away.