algorythms... Haldanean, Buhlmann and RGBM

[isp475]

I was reading a little more on the Uwatec, Suunto and Aeris/Oceanic lines and found that each run a different algorhythm. The Aeris and Oceanic: modified Haldanean which utilizes 12 tissue compartments. The Uwatec: Buhlman which checks 8 tissue compartments and in some models monitors microbubbles and the Suunto which is a RGBM model. Does anyone know enough about these models to explain the benefits or not of them, such as monitoring 8 vs. 12 tissues.  <br> <br>I guess it really comes down to what your LDS sells unless you want to drive several hours to make a purchase from a different shop and then mail the product each year for it annual service?  <br> <br>Thanks

[tbrown]

I missed this question, so you may have already found the answer that you where looking for. I guess the short answer is there is no short answer. Tissue compartments are a theoretical model of the body. Each part of the body loads N2 at different rates, and also off gases at different rates. For instance blood absorbs N2 rather quickly, and bone much more slowly. Instead of doing a model for every tissue in the body, Haldane came up with the theory of compartments, which is just a mathmatical model reflecting that parts of the body absorb and offgas at different rates. His original model was based on 5 compartments, the Navy tables on 6 compartments, and the PADI RDP on 14. There are some computers that use as many as compartments as 24 compartments (but I could not name one off hand). Most seem to use between 8-12. Now the big question seems to be which model is better, and the question cannot really be answered. These are all theoretical models and because of that there is NO guaranty. People have followed the tables (or computer) conservatively and still got bent. Others have blown their profiles completely and not suffered any symptoms. This really is not an exact science, so bring your pioneering spirit, and never push the limits of any model, computer or table.

Resources consulted
PADI Encyclopedia of Recreational Diving
PADI Dive Master Manual
Notes from lecture on the science of diving, history of diving and physiology of diving.

[freedivernd]

I have a suunto mosquito and have heard from folks that have suunto and other brands to compare that the suunto is slightly more conservative. Maybe doesn't tell you much.. and of course, it's nothing I've checked out. Just heard. Being a freediver I don't worry too much about getting bent or the nitrogen loading.

Fred