RGBM & Fast Decent

[BigJetDriver]

Folks,

We are forgetting that all on and off gassing is time/dosage related. We add our descent time into our bottom time, and we use a slow ascent rate with stops if necessary to compensate for the fact that rates for on and off gassing are not linear in nature. We do this in various ways with various models, but we still do it.

 

[DepartureDiver]

Fast descent in bubble theory aids in crushing micro-nuclei reducing the number of nuclei that can form bubbles on ascent. Slow ascent allows off-gassing, minimizing growth of existing nuclei.

Ralph

This is correct. While most would think a faster descent would create more ongassing, a bubble model is viewed differently and a faster descent is beneficial (but which might also have some adverse narcosis issues). Theoritically, this has a benefit for divers using trimix with either higher helium or lower oxygen. This can be be viewed as the bubble not being allowed to grow when breathihg trimix during the descent. A very technical physics presentation is given in an article by Eric Maiken on this. However, will all of this said, while I have no problem with fast descents (i.e. 100 fpm) on "shallower tech dives" (i.e. 200' or less), if they are any deeper, I find the slower descents easier and will average about 60-70 fpm.

 

[kf6cxf]

I was curious if a rapid decent (Less then 1 min) to a depth of say 100 feet, had any bearing on NDL's in the RGBM model?

just want to add this link

http://www.rgbm.mares.com/html/eng/rgbm/video.asp?id=8&lang=eng