Re: RES: [PSUBS-MAILIST] Ambient pressure design considerations

[DJACKSON99@aol.com]

Hello Stan 

I'd sure like to know the recommendation in the NOAA Dive Manual for 2 persons.  Seems to me that 2 people in an ambient submersible maintaining 30 feet and exhaling into an exhaust line would do better than 2 scuba divers swimming and enduring the cold.  Would that not be true? If you were not exhaling into an exhaust line, I'd venture to guess that the answer is somewhere around 3 cfm per person.

Also SportSub now has a Dry Ambient model. http://www.ivccorp.com/

Doug Jackson
http://jackson.parcabul.com/sub/index.html


In a message dated 11/3/2003 8:35:12 PM Eastern Standard Time, SFreihof writes:

> Hi Jorge;
>  
> To be correct, the Sport Sub is an ambient semi-dry sub.  It is not a dry sub any more than it is a wet sub.  The cabin itself serves as the ballast tank, and the water level in the cabin determines its buoyancy.  You sit in water with your head in a bubble.  There is no hatch.  The bottom is open.  To enter the sub you have to dive under it and swim up into it.
>  
> Conversely, an "ambient pressure dry" sub has a dry cabin.  The term both describes and defines the design.
>  
> The Sport Sub has a 'continuous flow' cabin air flush, but the drawback is that the air consumption is high.  The flow rates required per person have been studied in underwater habitats and are detailed in the NOAA Dive Manual which I can look up for you if you'd like.  The point is you have to carry a lot of air to do it.  Breath moisture is a minor consideration because you are operating in a humid environment with warm air encapsulated in a cool shell.  Condensation is 
> unavoidable, so plan on it.
>  
> Stan