Nova Tech: Northern Virginia's Technical Diving Community

Meetings > 3-13-2002

Second meeting:
Wednesday, March 13th, 2002; 6:30pm
Main Street USA Grill
Topic: Deco/Stage Bottle Rigging; Standard Deco Gasses

Wednesday March 13, 2002 marked the second meeting of the Nova Tech Divers. This community is the result of like-minded divers wanting to embrace what is deemed the safest method of technically oriented diving. The goal of Nova Tech Divers is to move towards, and outline a path for its attendees to become DIR (Doing-It-Right) divers and to stress the importance of diving as a team. We are not instructors, we are not a club, we are a loose group of divers who meet to discuss tech diving.

On the first meeting we covered general DIR gear set up and provided, in the time available, reasoning
behind the DIR gear configuration methods and DIR philosophy. We hope to now select a particular topic
area for a meeting and deal with the gear, the procedural and the philosophical aspects of the topic.

This months topic was decompression. The meeting began with a review of the selection, rigging and
marking of a basic deco bottle, reg & spg. This was followed with discussion of appropriate positioning of
the deco bottle on the harness and deployment of the deco reg, with emphasis on the extreme importance of
buddy observance/awareness (and assistance, if necessary) during the gas switch process.

The discussion then moved off of equipment and onto deco procedure & physiological considerations. Todd
discussed issues concerning advisability of diving a bottom mix with a low PPO2; CNS & OX/TOX
considerations for single and multiple day diving situations; CO2 retention; how long & why you should
sit on a gas switch; and why, when and where, gas breaks (from your deco gas to your backgas) are needed.

Dave discussed the benefits of using the DIR recommended standardized gases for both bottom mixes
and decompression gasses based on depth ranges (0-100, 110-150, 160-200 etc.) as opposed to using the
"perfect" mixture for any given depth, and how this protocol enables the diver to begin to actually learn
& understand decompression as opposed to being tied to a set of tables or a dive computer. This discussion
expanded into the advisability of using helium in all diving gases even below 100 fsw. Allyson attested to
the dramatic difference she noticed even when using a 30/30 mix at Lake Rawlings (maximum depth < 60 ffw) several weeks ago.

The meeting concluded with Todd's announcement that he had arranged for George Irvine, Project Director of the Woodville Karst Plains Project (WKPP), and dive partner Pina Porceddu to travel to our area and
address the Nova Tech group on April 13, 2002. This is a tremendous opportunity to hear the whys and the
wherefores of the DIR method of diving from one of the originators of the system. Please check the Nova Tech web site for additional information. We will need a head count so we have enough chairs so please email us if you plan on coming. Currently We have one fellow coming over 240 miles one way to attend the presentation! It will be WELL worth it to your diving career.

http://home.earthlink.net/~toddclagett/NovaTech/

PS - We (Todd, Dave & Allyson) will be diving at Mt Storm this Sunday. Dave hopes to have his new Gavin Short- Body HDPE scooter up there, Todds will be there for sure. Current forcast is in the mid 40's (water will be 60 +), if the front moves a bit faster we may see an air temp in the 50's. Come out and practice, get your gear squared away and get ready for those "real dives".