Foreword
This content is the closed-circuit rebreather diving and design philosophy of one man who for two decades (as of this initial 2019 publication) has been seeking to develop and refine his equipment and the skills necessary to adapt and perform maximally in the underwater environment. Michael Lombardi has numerous hundreds of hours of rebreather experience, diving both commercially available units and his own designs. There is a wealth of information presented here on topics often not discussed during rebreather training courses.
One such topic, scrubber bulk loading, is an often-little discussed aspect of rebreather design and dive planning. Here, its cause and the effect on scrubber duration are clearly presented. Additionally, how many rebreather divers know whether their bailout valve will provide an adequate flow of gas in open-circuit mode for emergencies at depth? Some do, but many do not, and the discussion on the coefficient of volume values of fittings used to plumb a BOV will be informative for those readers. Further, for those involved in scientific diving or for advanced recreational divers endeavoring to write better dive plans, the section on Activity Hazard Analyses is very useful. These and other topics are presented in detail, with references to source material, allowing the reader to delve deeper into the topics presented.
You may not agree with the author on everything presented here but you will find Michael’s design and diving philosophies to be thoughtful, well researched, and worthy of consideration. I have been fortunate to have worked on projects with Michael in the past, and through many hours of discussions with him on how to best use rebreathers for scientific diving, I have changed the way I approach CCR diving and dive planning. Whether you are buying a rebreather or building your own, time spent reading this material will be time well spent.
Jeff M. Godfrey
Diving Safety Officer | University of Connecticut
CCR Instructor #13375 | Technical Diving International