Seems fairly comprehensive.
Any particular reason dives 13&14 are with 50% and dives 15&16 (deeper) are with oxygen?
If I were planning those dives, I'd likely reverse the deco gas selection.
Reminds me of NAUI Cave1 where they took everyone else's curricula and added a little bit more. 30/30 and 25/25 that must be to allow graduates to blend in anywhere
Barring some really weird or exceptional profile requirement/need, I wouldn't use 50% as a deco gas for a 100ft dive. And I would really hesitate to use it for slightly deeper 25/25 dives too.
Marc, you'd be correct in doing that. However, your main concern as a diver would be to plan the most efficient decompression possible.
In class, students are usually introduced to deeper diving by progressive steps. The deeper switches on the 50% are simply for the minimum gas advantage. Students will have more bottom time when they generally are a little more nervous and may consume more gas at depth. Having more gas allows us more opportunity to learn and reduces time/gas pressure. So, while the 50% is not as optimal from a deco standpoint, experience has taught me that it is a better tool for beginning experience dives.
In my Tech 1 class with Andrew, we dove to 100 feet to start and switched to 50% at 70 feet. We did the same in Bob's Tech 1. I did the same in my TDI courses as a student.
I would keep my students on 50% throughout the course, but many want to use oxygen during the class for the experience. Using it during the next phase will demonstrate how minimum gas will change based upon having to ascend to 20 feet before the switch. The last two dives to 150 feet with the switch to 50% at 70 feet will be what they will be doing after class.
Diving education often takes more factors into consideration than they way we normally dive.
Rjack, most recreational programs have been built off the foundation of the US Navy and L.A. County. GUE came from NSS-CDS and NACD. Programs are built upon programs. When I joined PSAI they wanted skills done with flooded masks as well as masks on and off. Some students who can perform with a mask off have problems with doing skills with a flooded mask and must overcome their perceived discomfort.
It's no secret that I borrow from GUE and UTD. Since I started my tech career with GUE training, that principle of primacy kicks in, and having had AG and MHK for DIR-F and Tech 1, Bob Sherwood for GUE-F and Tech 1 and Ed Hayes for GUE-F, and completed my internship with Bob before deciding joining the GUE instructor corps wouldn't make me happy, I find all of DIR valuable. However, unlike most of you who didn't have a lot of diving experience before entering the DIR world, I had 18 years of experience as a diver and ten years of experience as an instructor at a headquarters for an agency for which the top 1/3 of GUE instructors taught recreational diving.
While they could teach an old dog new tricks, I learned so much more from other organizations as well. As Bruce Lee said, "Absorb what is useful."
Many of my students want to take advantage of this knowledge, but I get so many from GUE who don't want to deviate too far from DIR. As a proponent of DIR onewould think you would want more divers being taught better skills, better gas management, and one would also think you'd be totally supportive of an industry professional like myself helping the deep air guys begin to retool to the 21st century. It's not my agency. If it was, I would seriously think about getting rid of any deep air diving past the 150 foot level. Extended range programs are very popular in Asia where they can't get mix, but 180 feet IMO is quite deep. I don't support the PSAI Narc Management program or the Extended Range courses past that point. But, I'm just one voice.
That voice just made them take one small step forward. Cut me some slack.
