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This is a multi-part message in MIME format. --------------2EE9A3066D7DE9E308E4FDA4 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Here's my TDI instructor's (and friend) take on the deep air course...... Steve Lewis wrote: > Ben: I did not know of the current debate about deep air, but this is > something that surfaces regularly > and seems to attract lots of attention from under all the rocks... Here's > my take on the reason for some sort of extended range course. > > Firstly, an extended range course is not about diving deep on air... > whatever that is. As you know from experience, up here in the great lakes > deep on air is anything beyond 130 feet. The cold, lack of vis, and general > quality of the environment contribute greatly to getting mentally out of > shape real fast. So naturally, dives to 200 feet on air in northern > conditions are extraordinarily tough and not called for in the course. I > can't speak for > instructors working in Florida conditions, but I do not feel it necessary > to conduct dives in this range to accomplish what the course is intended > to. > > The extended range course is more about equipment management (more tanks, > streamlined gear configuration, equipment choices), gas and deco management > (long exposures with very high decompression debits and large gas volume > requirements), and physiological task loading (how do candidates manage > in-water emergencies, how do they react to very long periods of time spent > at the shallow deco stops, and do they recognize the effects of narcosis > and how do they react to it), and last and most important, very detailed > dive planning. Diving deep on anything for a long time is a pain in the ass > to orchestrate > > It is necessary on the course to gain experience that can carry over to > trimix. A trimix course is about very simple math and some basic formulae > all the nitty-gritty in-water and equipment stuff should be handled long > before throwing someone on a helium mix that'll get them totally screwed if > they > start blowing off deco and missing scheduled runtimes. > > I think the "deep air" courses kind of grew out of this need... "let's see > how these folks handle such and such a situation" so to speak. Don't forget > that > trimix is a relatively new tool for recreational divers, and is still > misunderstood by masses of people. Deep air on scuba has been around since > the forties and it's still a hotly debated point and misunderstood by > masses of people so why expect anything else. To begin with one has to > define it and there's no agreement there. British Sub-Aqua Club courses > teach level II divers to 160 feet as standard... and the waters around the > UK are never warm or particularly noted for great vis. > > Anyhow, finally it's a question of choice. I use light trimix on dives in > Lake Eire on wrecks as shallow as 170 feet. For short duration dives the > decompression debit is outweighed in my mind by the benefit of being able > to conduct working (data gathering) dives with a clear head. However, I > have conducted solo dives to 200 feet plus on air... but I do so with an > understanding that my reactions will not be their usual "razor sharp" > selves. > > Ben, hope this answers some of your questions... and yes I do think there's > room for an intro to trimix course. By the way, feel free to post this on > the net if you wish. And what the hell are folks refering to? Who killed > whom? > > Steve Lewis > TDI CI 007 > doppler@ea*.co* > > b.greenhouse@ut*.ca* on 10/08/97 02:14:07 PM > > To: Steve Lewis/PGComm > cc: greenhar@mu*.CI*.Mc*.CA* > Subject: Deep Air > > Steve > > Just wanted to get your opinion on this deep air debate (that you > may or may not know is going on on the internet). A lot of people are > badmouthing TDI for insisting on deep air before trimix, saying it is > just a moneygrab. Others are saying that deep air is basically only a > course on air management, decompression theory etc.... What do you > think? > > Ben > > begin: vcard > fn: Ben Greenhouse > n: Greenhouse;Ben > org: University of Toronto > email;internet: b.greenhouse@ut*.ca* > x-mozilla-cpt: ;0 > x-mozilla-html: TRUE > version: 2.1 > end: vcard --------------2EE9A3066D7DE9E308E4FDA4 Content-Type: text/x-vcard; charset=us-ascii; name="vcard.vcf" Content-Transfer-Encoding: 7bit Content-Description: Card for Ben Greenhouse Content-Disposition: attachment; filename="vcard.vcf" begin: vcard fn: Ben Greenhouse n: Greenhouse;Ben org: University of Toronto email;internet: b.greenhouse@ut*.ca* x-mozilla-cpt: ;0 x-mozilla-html: TRUE version: 2.1 end: vcard --------------2EE9A3066D7DE9E308E4FDA4-- -- Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'. Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'.
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