Northwest Dive Club

Ahead of whenever KISS/TDI, etc get a level 2 course for my GEM up and running (and of course the availability of the non recreational parts), I need to start some tech classes to get my tech fundamentals back up to speed again.

Deco Procedures. (what we did in the old days was probably scary by today standards)
Advanced Nitrox (40-100%)
Tri Mix

and any other suggestions for classes?

Next of course would be one instructor I can follow all these through, as I'd rather not dance around between shops, organizations, and instructors. I could care less about the certifying organization, rather the instructor and what he/she teaches.

Any help appreciated, feel free to PM me if so inclined.

You will soon find that switching between OC and CCR (albeit SCR) is a bad thing. If you are going to go in the rebreather direction, stick with someone you are comfortable with and who can do ALL of your training. Sorry if I am sounding blunt, but I'm starting to see a scary trend here.

I don't mean to sound like I'm being a jerk, but I'm actually curious as to how one would approach technical diving with a unit like the GEM. The thing about SCR that baffles me is that they are all- even the GEM- one trick ponies. They extend the gas in a given tank by dribbling it out and scrubbing part of it out. Whereas a CCR can adjust p02 levels for virtually any depth, SCRs.....don't do that. SO, if you want to go to a given depth on an SCR, you have to dial in a mix for that depth....and there you are. Let's say you want to go to, oh, I don't know, let's say 200'. A good mix for that depth would be something like 16/50. (more helium would probably be better, but whatever) a common profile for this kind of dive would be 5 minutes descent, 20 minutes on the bottom, start your ascent at 26 minutes. If you do the whole dive on this mix, You're going to be doing 176 minutes in the water doing deco. It totally sucks, you HAVE to add some deco gasses. Adding 50% and 100% make this look almost reasonable- down to 77 minutes, and you could probably get away with al40s of the deco gasses. But I don't really know- I calced this as an OC dive, because when I tried to use SCR on vplanner, it wanted me to fill in a bunch of stuff I didn't understand. Guess my only point is that both OC and CCR seem a lot simpler for this kind of diving, to me. The only folks I'm aware of using SCRs for tech diving are the WKKP, which is one place that kind of makes sense- where they're pushing 20 hours into caves at relatively consistent depths...and even they are looking pretty hard at different CCRs these days, according to the rumor mill.

So, yeah, Jeff- you probably DO want to take advanced eanx/ deco (usually bundled into one class) and trimix, but doing it with the GEM is where it's going to get interesting, because nobody else is doing it that way, that I'm aware of. Sit down with your instructor and talk about your goals. I'm curious to find out how its all going to work, myself.

No offense taken Josh. The GEM "today" isnt the unit. Obviously. But if you read up on rebreatherworld, guys are taking SCR's (Satori, Tres Presidentes, etc) to 300ft. Gas Switch blocks allow you to change gases, and one can easy switch to OC for Deco. The history of the GEM itself, is it was born in a 300ft cave dive. The GEM as it sits today was dumbed down to rec diving. I've spent time talking with folks who prefer not to be named throughout the US that do, do this sort of stuff with SCR's.

Whether I actually ever will do 200ft with the "future" GEM, I dont know. Maybe by then I'll get a CCR anyways. But for today, its serves a purpose for to be able to do long dives with folks doing doubles. If its future holds out, then more. If it doesn't, I'll decide then. For all I know, I'll hate the CCR/OC switch as fishb0y notes, sell the GEM, and then just go SM.

For what I paid for the GEM (and trust me, I got a HELL of deal) I wont loose anything on it.

To summarize for the mindreaders: I'll be taking my rec only oriented GEM and GEM 1 class. And diving within rec limits. Take whatever advanced classes I can on OC, and when the GEM Level 2 class comes out, and the upgraded hardware, I'll be ready. If it never comes out, or I hate it, I have SM to fall back on. Or just stay within rec limits on Back Gas.

The great part about scuba is you usually have options...

I'm genuinely curious about this, because you're the only person I know doing it. I would probably have advised you to get a good deal on a used CCR, but I'm admittedly biased.

Sidemount is pretty sexy, but also a fair bit of work to dial in......although I think it is the wave of the future. My gut feeling is that 10 years from now, were going to see a progression like:

Single tank

Sidemount dubs, OR something like the Gem, less backmount dubs

CCR dominating below 200'

Hardsuits becoming viable.

Diving articulated hard suits must be a major bitch. I'd imagine with more advanced gyro's today, they are alot easier. Fly by wire even better.

Jeff Pack wrote:Diving articulated hardsuits was a major bitch. I'd imagine with more advanced gyro's today, they are alot easier. Fly by wire even better.

Wow, you dived hardsuits? Salvage diving, or what?

Jeff Pack wrote:Diving articulated hardsuits was a major bitch. I'd imagine with more advanced gyro's today, they are alot easier. Fly by wire even better.

Which Suit(s)?

D

Jeff Pack wrote:No offense taken Josh. The GEM "today" isnt the unit. Obviously. But if you read up on rebreatherworld, guys are taking SCR's (Satori, Tres Presidentes, etc) to 300ft. Gas Switch blocks allow you to change gases, and one can easy switch to OC for Deco. The history of the GEM itself, is it was born in a 300ft cave dive. The GEM as it sits today was dumbed down to rec diving. I've spent time talking with folks who prefer not to be named throughout the US that do, do this sort of stuff with SCR's.

Those are SCR dives in CAVES; its a static environment. Figure out the deco penalty you get on SCR and you will drift halfway to Japan before you're ready to surface here. And your buddies will not be pleased either. If you change to the 8:1 mouthpeice the deco penalty is hideous. Unless you plan on switching to 100% O2 at like 50-60ft and relying on the ppO2 drop to make it breathable and "optimal".

Besides all that, you're listing "trimix" as if its a course you can just whip off in a weekend then go do the MT6 on your GEM the next. At this point, I don't see any operator or private boats who are going to eager to support your transition into technical diving as the liability around your "plans" is getting rediculous.

Jeff,

If you are primarily going to switching to rebreathers for technical diving, I agree with the previous comments that you should seek out a rebreather instructor that can take you where you want to go.

Unfortunately there are not a lot of SCR technical instructors that will be able to help you with what you are looking for.

The closest would probably be Mel Clark, she teaches OC and rebreather technical diving classes.

That said, I understand your SCR is recreational and doesnt do today what you are looking down the road to do with it, but sounds like there are "plans in place" to take it there.. I wouldnt hold my breath though.. Dont count on manufacturers releasing something thats just a rumour. (look at Scubapro being 4 years late with trimix on Galileo)

SCR's are quite capable of doing 400+ foot dives. The GUE crew does those dives with RB80 SCR's and its specifically built for those kinds of dives.. you plumb your deco gas into the loop when you switch to deco (just like OC) and it basically extends your deco gas same as you back gas.. Sure, there are no computers to calculate and adjust best-mix PO2.. but its completely doable with an SCR using gas switch blocks.. Its just very different from traditional CCR techical diving where the computer does all the work, with SCR's there are no computers, sometimes no O2 sensors even. Its all manual.

Go talk to Mel Clark if you are hell bent on technical diving with the GEM.. She will give you honest feedback

Koos

kdupreez wrote: Go talk to Mel Clark if you are hell bent on technical diving with the GEM.. She will give you honest feedback.

Mel is not a GEM instructor. The only GEM instructor in Washington is Craig Willemsen, who Jeff is apparently going to take his initial class through in a week or so. Craig is also a CCR instructor and clearly understands the differences between the types of units and their capabilities.

I would urge you, Jeff, to sit down and have a long, heartfelt talk with Craig about what you think your intentions are and what is or is not possible based on existing technology and knowledge. I cannot imagine that he would concur with what you are saying here.

When you are doing deep tech dives you are not just out to have a "fun time"....you are out to stay alive and help your buddies stay alive. Doesn't it make sense to choose a path specifically designed to do what you want to do, instead of trying to make something work that is not designed for it?

- John

Joshua Smith wrote:

Jeff Pack wrote:Diving articulated hardsuits was a major bitch. I'd imagine with more advanced gyro's today, they are alot easier. Fly by wire even better.

Wow, you dived hardsuits? Salvage diving, or what?

shhh..

kdupreez wrote:
SCR's are quite capable of doing 400+ foot dives. The GUE crew does those dives with RB80 SCR's and its specifically built for those kinds of dives.. you plumb your deco gas into the loop when you switch to deco (just like OC) and it basically extends your deco gas same as you back gas.. Sure, there are no computers to calculate and adjust best-mix PO2.. but its completely doable with an SCR using gas switch blocks.. Its just very different from traditional CCR techical diving where the computer does all the work, with SCR's there are no computers, sometimes no O2 sensors even. Its all manual.

Finally... thx Koos

I'm not taking any SCR training here locally, I've found training elsewhere that more aligns with my goals. There's quite a network of SCR users.

Jeff Pack wrote:

Joshua Smith wrote:

Jeff Pack wrote:Diving articulated hardsuits was a major bitch. I'd imagine with more advanced gyro's today, they are alot easier. Fly by wire even better.

Wow, you dived hardsuits? Salvage diving, or what?

Cant talk on specifics of those days, but were deep water rescue operations. You'll have to read between the lines on this one.

i just saw 2 Jim suits at the Keyport museum yesterday. I have a couple of buddies who were 1st class duvers that used them. I'll ask to see if they remember you.

defied wrote:

Jeff Pack wrote:Diving articulated hardsuits was a major bitch. I'd imagine with more advanced gyro's today, they are alot easier. Fly by wire even better.

Which Suit(s)?

D

what suit?

fishb0y wrote:

Jeff Pack wrote:

Joshua Smith wrote:

Jeff Pack wrote:Diving articulated hardsuits was a major bitch. I'd imagine with more advanced gyro's today, they are alot easier. Fly by wire even better.

Wow, you dived hardsuits? Salvage diving, or what?

Cant talk on specifics of those days, but were deep water rescue operations. You'll have to read between the lines on this one.

i just saw 2 Jim suits at the Keyport museum yesterday. I have a couple of buddies who were 1st class duvers that used them. I'll ask to see if they remember you.

kewl

These are SDVT-1 and DEVRON-5 guys. All that secret squirrel stuff from the 70's and 80's. One of him even worked with the Glomar Explorer. Even though he doesn't give specifics he does give good stories.

They may very well then,

John Rawlings wrote:

kdupreez wrote: Go talk to Mel Clark if you are hell bent on technical diving with the GEM.. She will give you honest feedback.

Mel is not a GEM instructor. The only GEM instructor in Washington is Craig Willemsen, who Jeff is apparently going to take his initial class through in a week or so. Craig is also a CCR instructor and clearly understands the differences between the types of units and their capabilities.

I know Mel is not a GEM instructor, but she is an instructor for KISS and quite a handful of other SCR and CCR brands as well as OC technical diving (which what Jeff was looking for) and she knows the landscape like nobodies business, additionally Jeff has a rapport established with her after the rebreather demo days he attended with them.. So I thought Mel could give him really good guidance on where to go from here

The point is, Jeff should go talk to someone like that (and sounds like Craig) to get the full lowdown on what the best approach would be moving forward and plot a training path for him toward his goal.

Its not going to happen overnight and I dont think Jeff is expecting it to either.. thats why he came to this group to ask for guidance on "who" the right people (Instructors) are to approach for direction on how move forward with his goals. And I am confident they will have no reservation to tell Jeff what are bad ideas or what are not viable options for reaching his goals.

We can criticize and tell Jeff which way from Sunday on what he should not and can not do, but that doesnt provide a constructive answer to his question. The source of truth about whats viable will be the instructor that maps out his training path..

So, to answer Jeff's question, I suggest go talk to Mel Clark or Craig Willemsen (id recommend talk to both) about the design intent and future capabilities of the GEM and if that maps with your goals and then let them help you put a plan in place for training towards those goals.

K

Jeff Pack wrote: I dont recall the name, we called it "The Lunch Box", because you get all closed up in it, and you often wound up re-eating your lunch. The stability was so poor, if you made the tiniest mistake in propulsion, it would spin uncontrollably and you'd puke your guts out. Best thing to do was just release the controls and hope the gyro's would stabilize you.

So the Navy sent you down to perform deep water rescues in a suit you could barely control? I guess I wouldn't put it past them.

All though I remember the OceanWork's and WASPS in the navy. All SEAL rescue diving was performed using SDVT's because the only way people survived at those depths were generally in a submarine, and they had the universal locking collar on that. No external mating was required (Allthough at shallow depths (to 400fsw), they would tend to have a Navy Diver on the outside, but in a hardhat, not a 1atm suit.

Back to the topic at hand:

Wouldn't you have a solid understanding of CCR's from diving yourO2 CCR, Mk15, or Mk16 (This one might be too new) mixed gas (I imagine you had training in all of these as you were trained to dive a hard suit)?

D

Jeff Pack wrote:

fishb0y wrote:

Jeff Pack wrote:

Joshua Smith wrote:

Jeff Pack wrote:Diving articulated hardsuits was a major bitch. I'd imagine with more advanced gyro's today, they are alot easier. Fly by wire even better.

Wow, you dived hardsuits? Salvage diving, or what?

Cant talk on specifics of those days, but were deep water rescue operations. You'll have to read between the lines on this one.

i just saw 2 Jim suits at the Keyport museum yesterday. I have a couple of buddies who were 1st class duvers that used them. I'll ask to see if they remember you.

Unless they had extremely-extremely high security clearances, I doubt it. This was all military ops.

Like an SSBI/SCI/ PRP type clearance? That would make sense if you were EOD, a SEAL(though, the divers that did rescue were typically NEDU weenies, I have never met a SEAL that did "deep water rescue". And DEVGRU-or whatever they are calling it today-doesn't spend that much time in the water.) Salvage divers doing some sort of nuclear recovery would need it. and they are pretty much the only ones that I have worked with that did that kind of work.

But then, I was just a grunt with a medical bag....

On the other hand, they never ever really happened anyways...

One more 'really' would have sold it, damn.

Jeff Pack wrote:I really really really cant say beyond what I already have on this. Much as it would be a couple of great stories. On the other hand, they never ever really happened anyways...

How about my questions? You can answer those.

D