Rec Vs. Technical???

[tursiops]

Also, I don't find anything in the standards (old version though, I can't seem to find a more recent one than 2003) saying it is air only, that would also go against what is on the website, which allows 160fsw (ie 48m)

Something is wrong here...

I don't see the conflict. My TDI Extended Range class took me to 180 ft on air. The standards still allow that.

 

[Octopusprime]

I'm not a tech diver, so not qualified to comment on much of the discussion here. Someone pointed me to a nice article a few weeks ago that goes well with the discussion here - https://www.tdisdi.com/not-all-tech-divers-are-aholes/ It's on the internet, so it's got to be true, right?

Loved the artical... The forum was closed now it is open again... Can we get back to diveing? I would love to hear from any other divers that regularly dive Lake Michigan especially the IL WI side.

Any particular wrecks to research? Maybe starting at the 60-90ft range and graduating to 90-100ft. I do not need to go to the bottom if there is plenty to see on the top of the wreck. I enjoy taking video while I dive and map wreck on a slate while I'm down...

I have been practicing wreck skills to finish wreck Specality this summer so any open easy starter penetration suggestions are great.

 

[Subcooled]

I am a recreational diver NOT a tech diver but have some questions to see if a tech course is something I should pursue.

As a recreational diver you do an optional 3 minute safety stop. As a technical diver you do a mandatory longer stop, and possibly a few more stops. This is not a radical change. What changes though, is that if you violate the stops then you get some real damage. You end up in a hospital (or you die).

It seams that many of the things I find my self interested in going to see are in 100-140 ft in lake Michigan. However at 120ft only having 13 min of bottom time seams like a lot of work and time for 13 min of bottom time.

You would benefit from a course that teaches decompression diving. It's nothing special. You just spend more time at given depths prior to surfacing. Add nitrox/oxygen, and the stops will be a bit shorter.

I would assume I would go to Dual back gas + stage bottles which means loosing the BCD and going to a wing and back plate

At depth you will need more gas per minute. Hence double tanks. You cannot surface immediately. Hence two first stages and two regulators. If one fails you have another.

How many different gasses will I need

None, but switching to oxygen really make you stops shorter. Recommended, as long as you can afford an oxygen clean system.

I see a lot of guys in LM with Dual Back gas and 2 stage bottles, but have seen some with dual back gas and 4 stage bottles.

Back gas for very deep dives is usually a helium mix. The breathing gases for the up journer are commonly 50% oxygen and 100% oxygen. If the dive is very deep (more than 180ft) then more gases are used.

 

[HIGHwing]

I don't do either, but I was talking about this with a tech instructor recently and she posed this question: So you have to bail out at the end of your dive due to a CO2 breakthrough. Is this the ideal time to have your first OC deco experience?

That's a great point, but it doesn't really apply to the reality of the situation. If you bailout from a CO2 hit and need to finish decompression, you can be assured you won't be relying on your skills alone; you'll be relying on the skills and probably every drop of gas your entire dive team brought on the dive. The question she posed at first glance sounds astute and philosophical, but in truth it's the type of question posed by someone who has not really not wrapped their head all the way around the role and consequences physiology plays in a CCR dive. Based on video evidence, a "few" credible things I've studied, and speaking to a CO2 hit survivor and someone who has rescued a CO2 hit victim two miles back in a cave - I believe a CCR diver is very unlikely to live through a CO2 hit at depth/time requiring decompression without external assistance (i.e. autonomously). The bottom line is you're very likely to run out of breathing gas.

The other point to be made is by the time you get your CCR w/deco card, you've done hundreds if not thousands of minutes in the water with many of those dives ending in a bailed situation. Truth be told, with an eCCR behaving properly a 300+ft CCR Trimix dive is no more difficult than a 60ft CCR drift dive across the reef. Assemble, Turn Unit On, run checklists, and dive. Assuming you use automatic setpoint control, you shouldn't even need to touch a button during the entire dive whether it's 60ft or 300+ft. The only complication is selecting the Dil and dragging more or less bailout/deco gas.

 

[Octopusprime]

Subcooled great info...

 

[cocoajoe]

My take: There is no middle ground between tech & rec. At least I've not found one. You either have to go full tilt and get training and equipment or be satisfied with rec.
That means time, expense and commitment. For me, all I wanted was a few more minutes on 90-100 ft wrecks that could/would include a FEW minutes of deco. I didn't want to do doubles or expensive helium (that's what happens in some agencies) long hangs etc. But there really isn't an agency (that I've found) that teaches 'a little deco'
Just my take

 

[KevinNM]

But there really isn't an agency (that I've found) that teaches 'a little deco'
Just my take

GUE Rec 3 course does this. It's in doubles with trimix, but it is classified as a rec class.
Recreational Diver Level 3 - Trimix Diver | Global Underwater Explorers

 

[Dr. Lecter]

That's a great point, but it doesn't really apply to the reality of the situation. If you bailout from a CO2 hit and need to finish decompression, you can be assured you won't be relying on your skills alone; you'll be relying on the skills and probably every drop of gas your entire dive team brought on the dive. The question she posed at first glance sounds astute and philosophical, but in truth it's the type of question posed by someone who has not really not wrapped their head all the way around the role and consequences physiology plays in a CCR dive. Based on video evidence, a "few" credible things I've studied, and speaking to a CO2 hit survivor and someone who has rescued a CO2 hit victim two miles back in a cave - I believe a CCR diver is very unlikely to live through a CO2 hit at depth/time requiring decompression without external assistance (i.e. autonomously). The bottom line is you're very likely to run out of breathing gas.

This may be true for cave CO2 hits with especially bad BO planning, but speaking as someone who had one a couple months ago at 240' while solo, they're certainly survivable autonomously if you catch them early enough and have the BO you need. Yes, I upped my deep BO gas plan significantly afterwards seeing how fast I burned through gas once my breathing rate spiked, and yes it was a tricky moment to control myself and time the transition from DSV to OC...but the actual 45 minutes of OC deco I needed to do (hit happened relatively early in the dive) was not a problem in and of itself, and I'm not sure what real assistance a buddy could have provided.

 

[Octopusprime]

My take: There is no middle ground between tech & rec. At least I've not found one. You either have to go full tilt and get training and equipment or be satisfied with rec.
That means time, expense and commitment. For me, all I wanted was a few more minutes on 90-100 ft wrecks that could/would include a FEW minutes of deco. I didn't want to do doubles or expensive helium (that's what happens in some agencies) long hangs etc. But there really isn't an agency (that I've found) that teaches 'a little deco'
Just my take

nice point... It is part if why I started this thread... Where does rec really end and Tec begin? My thought before was once you hit a deco stop you have exceeded recreational diving. But now I think of it as multi gas. Or more than a short deco? Kinda muddy but a couple people here have said you can easily do 120 on 36% nitrox for 30 min with just short deco even though that exceeds nitrox table. (Not that I'm going to try it)

this is spring and summer I'm going to lok for some 90-100 ft dives on 36% nitrox and see if I run out of gas before non deco time...

 

[hroark2112]

nice point... It is part if why I started this thread... Where does rec really end and Tec begin? My thought before was once you hit a deco stop you have exceeded recreational diving. But now I think of it as multi gas. Or more than a short deco? Kinda muddy but a couple people here have said you can easily do 120 on 36% nitrox for 30 min with just short deco even though that exceeds nitrox table. (Not that I'm going to try it)

this is spring and summer I'm going to lok for some 90-100 ft dives on 36% nitrox and see if I run out of gas before non deco time...

Don't do that.

Let me know when you figure out why!!