Portable Lightweight Decompression Habitat
Posted: Wed Aug 29, 2012 8:34 pm
Established 2005
https://nwdiveclub.com/
Yes, I've seen a few different cave habitats, but never one for open water. I'm really intrigued by the idea. Those last few deco stops just freaking kill me, on deep dives. The idea of getting out of the water, even partially, and maybe even having a snack and...wow, maybe even a hot cup of coffee?....is really amazing.DiveZen wrote:Cool! White Arrow makes one for cave diving (simpler). I've not used it, but it looked cool.
http://www.nick-toussaint.com/sump_diver/wa_habitat
Ok, after about 1 minute of thought, I realized that you could conceivably get away with half of a sphere... 450 lbs of upward force. Still seems to be the most challenging part of the problem where there is not already a hearty mooring buoy/block of concrete/professionally installed anchor.diverden wrote:So, I've been thinking about this and have "run the numbers." A 3 ft diameter sphere of gas (cozy!) is going to displace about 900 lbs of seawater. How is this "Portable" and "Lightweight" ? It obviously assumes you have something like a 1200 lb block of concrete with a chain on it where you want to use it.
Discuss.
(Assumptions:
the formula for the volume of a sphere is correct,
that the weight of seawater is about 64 lbs/ft^3,
the anchor 1/3 "heavier" than what it's holding down,
diameter of 3 ft is for the minimum imaginable size of a sphere for 2 people,
is one where you can barely touch the other side of it)
I'm not as good at the math as you, but when I said "portable" and "Lightweight" I was talking about the equipment as it sits, out of the water. I've seen pictures of a few habitats that used giant plastic tanks- the kind you might use to store water or gasoline underground- and were inflated and "stuck" to the ceilings of caves. This one breaks down to a single bag about the size of one person's luggage, if I read it right.diverden wrote:Ok, after about 1 minute of thought, I realized that you could conceivably get away with half of a sphere... 450 lbs of upward force. Still seems to be the most challenging part of the problem where there is not already a hearty mooring buoy/block of concrete/professionally installed anchor.diverden wrote:So, I've been thinking about this and have "run the numbers." A 3 ft diameter sphere of gas (cozy!) is going to displace about 900 lbs of seawater. How is this "Portable" and "Lightweight" ? It obviously assumes you have something like a 1200 lb block of concrete with a chain on it where you want to use it.
Discuss.
(Assumptions:
the formula for the volume of a sphere is correct,
that the weight of seawater is about 64 lbs/ft^3,
the anchor 1/3 "heavier" than what it's holding down,
diameter of 3 ft is for the minimum imaginable size of a sphere for 2 people,
is one where you can barely touch the other side of it)
[sarcasm]Well, my theory is that you anchor it to the bottom, and just expect that everything will work out in some magical fashion.[/sarcasm]CaptnJack wrote:How do you anchor it to the bottom yet drift?
couple of engine blocks?Joshua Smith wrote:[sarcasm]Well, my theory is that you anchor it to the bottom, and just expect that everything will work out in some magical fashion.[/sarcasm]CaptnJack wrote:How do you anchor it to the bottom yet drift?
And, perhaps, people might look at this idea and adapt it to their needs. I've been trying to think of a way to rig this up to our floating deco station all day.
... and the loss of O2 due to metabolism. ~= .6 l/m/personCaptnJack wrote:When you're breathing 100% O2 the gas in the habitat has plenty of O2 (from the air or 32% it was filled with and 100% exhalations) Not sure about CO2 accumulation however, I'd have to do the math.
For the 2 dives I've considered a habitat on, doing a shorter BT was a better option than the effort to rig it.
Breathing 100%, your exhalations have more than enough. I don't know anyone using habitats any deeper than 20ft anywaydiverden wrote:... and the loss of O2 due to metabolism. ~= .6 l/m/personCaptnJack wrote:When you're breathing 100% O2 the gas in the habitat has plenty of O2 (from the air or 32% it was filled with and 100% exhalations) Not sure about CO2 accumulation however, I'd have to do the math.
For the 2 dives I've considered a habitat on, doing a shorter BT was a better option than the effort to rig it.
So what would you say you were breathing, during your decompression?CaptnJack wrote: Breathing 100%, your exhalations have more than enough. I don't know anyone using habitats any deeper than 20ft anyway
Just take the reg out to talk and eat. I wouldn't sit there for extended periods of time breathing the habitat's gas. I just wouldn't be paranoid that the gas in the habitat wouldn't support life.diverden wrote:So what would you say you were breathing, during your decompression?CaptnJack wrote: Breathing 100%, your exhalations have more than enough. I don't know anyone using habitats any deeper than 20ft anyway
Point taken, of course. Still, it might work well in a lake, for instance- or anywhere not current sensitive- engine blocks and all. What about fixing something under a boat, maybe?CaptnJack wrote:couple of engine blocks?Joshua Smith wrote:[sarcasm]Well, my theory is that you anchor it to the bottom, and just expect that everything will work out in some magical fashion.[/sarcasm]CaptnJack wrote:How do you anchor it to the bottom yet drift?
And, perhaps, people might look at this idea and adapt it to their needs. I've been trying to think of a way to rig this up to our floating deco station all day.