Posts Tagged: ideas

Human Physiology and Diving from Tech Diving Mag

There is a new issue of Tech Diving Mag available that has some articles on diving physiology.  For those that aren’t familiar with the magazine here is a quick introduction.  Tech Diving Mag is an awesome resource for the latest technical diving research, experiences, and resources.  The motto is “Research – Development – Exploration” and Asser Salaam does an excellent job of adhering to that by combining contributions of technical divers from around the world.  You can read more about this magazine here:

This issue contains many articles that are near and dear to my heart but in this post I’ll just talk about the two that relate to the human body.  The first one is about the affects of descending and how they apply to human physiology.  Some of my dive buddies have seen incidents of heart attacks or other cardiac conditions underwater and I have always thought that it might be stress related.  Then I read this article and realized that it is just human physiology and pressure. In as shallow as 6 feet, 14% of the adult body’s blood volume shifts from peripheral circulation to central circulation causing the heart to increase output by up to 50% (Covington, 2014).  This is definitely a good argument to keep yourself in shape!

The second article is very interesting because it is something that I have been contemplating trying to do.  I heard about a group of technical divers that would breath 100% oxygen from 20′ all the way until they would reach the airport in order to avoid the no fly time.  Though I am not sure if this is just legend or not, it sure would be awesome to maximize the amount of diving you could do when on a trip.  The Divers Alert Network offers recommendations on the length of no fly time for divers performing different dives.  For a single no decompression dive the no fly time should be a minimum of 12 hours, for multiple dives per day or multiple days of diving it should be 18 hours, and for any decompression dives it should be more than 18 hours (DAN, 2002).  What Asser Salama proposes is a way to reduce your no fly time by using delayed surface O2 breathing.  He states that breathing pure O2 immediately after surfacing is less effective than breathing it starting 4 hours after surfacing.  The same holds true for Trimix blends, however the gains aren’t as substantial as with a Nitrox blend (Salama, 2014).  In this article, there are compelling calculations presented that may tempt me to start experimenting with this.  Have you ever experimented in this diving arena?  If so, what were the results?

These articles reminded me again that every diver is unique and you should know your own limitations.  Stay within your training level and stay fit for the type of diving you are performing.  Also, make sure you understand the risks associated with diving and ensure that you are willing to accept the consequences of your experimentation.


  1. Covington D. (2014). The Body – Descending. Tech Diving Magazine, Issue 15, 3-5. Available from:
  2. Salama A. (2014). Calculating the acceleration in post-diving no-fly time associated with breathing surface oxygen. Tech Diving Magazine, Issue 15, 23-26. Available from:
  3. Divers Alert Network. Revised Flying After Diving Guidelines for Recreational Diving.


This site has been a dream of mine since I started diving six years ago but could never find the time or just kept putting it off. I have since moved to the Pacific Northwest and acquired a GoPro so I feel the time is right to share the adventure.

Over the years I have had many experiences in diving, some good, some bad, and a plethora in between. I will be posting as regularly as I can about those experiences. I also hope to add many resources to include dive checklists, gear reviews, shop reviews, and trip reports.

I imagine I will be doing a bulk of the posts however I have asked the other members of DiveYeti to contribute as much as they can as their schedules permit. I hope to have this grow into a community of dive information sharing and story telling. The various personalities should help to make it entertaining. Until the next post here is one of my favorite pictures that encompasses, what I feel is, all of diving.