Nitrox table vs computer question

[Lizard Leg]

beaverdivers - but isn't the science above saying that my theoretical dive to 120 fsw on 32% with a max PPO2 of 1.48 for @ 5 minutes is “yellow light” safe, the other article says the same thing, while at the same time the science behind the course is teaching 1.4 is MAX?
I imagine Gandalf standing there at the back of the boat, with his NAUI shirt, a Lionfish spear instead if a wizards staff, smelling vaguely of Kalik’s and yelling “YOU SHALL NOT PASS!!!”

 

[beaverdivers]

beaverdivers - but isn't the science above saying that my theoretical dive to 120 fsw on 32% with a max PPO2 of 1.48 for @ 5 minutes is “yellow light” safe, the other article says the same thing, while at the same time the science behind the course is teaching 1.4 is MAX?
I imagine Gandalf standing there at the back of the boat, with his NAUI shirt, a Lionfish spear instead if a wizards staff, smelling vaguely of Kalik’s and yelling “YOU SHALL NOT PASS!!!”

Follow the guidelines.

Plan your dive to exactly 110' ( not " about " ).

After the dive download your dive computer, then if your computer shows that you executed the dive plan properly - "YOU SHALL PASS!"

Did your computer show an exact Max Depth of 110"?

Save the propeller at 120' for another dive after you have more experience.

If I were doing the dive, I would feel comfortable using 32% or higher.

I would limit my depth based on which part of the wreck that I wanted to focus on and which mix I chose to be best for that depth.

If I felt like I wanted to dive the propeller at 120', I would use 32%. However if I encountered heavy current or tough conditions, then I would limit my depth and not go as deep.

If I was working on a propeller at 120', then I would dive a lighter mix.

The difference is our experience level. I feel very relaxed at 120' - my heart rate is usually 60, my breathing .4 cuft/min and no workload.

I have done 1000's of dives at or below that depth using Nitrox.

How many dives have you done below 60'?,
or 80'? or 100'?

Are you ready for this wreck dive?

Good Luck & Good Diving!

 

[Lizard Leg]

Deepest to date is 51'. By the time we do this deep dive, will have about 30+ dives or so, deepest planned before Thunderbolt is 72'. The Thunderbolt dive is the deep dive portion of our AOW and one of the instructors we had for OW that we liked so much, we are going back to the Keys to do the AOW with him.

There will not be a lot of exploration on this dive, maybe 5 minutes I guess. He isn't telling me what "test" if any we will have to do at depth - wants to let us know at the dive planning session. On air, with my SAC of .7-.8 cuft/min, you can do the math - not a lot of time down there.

I figured on this profile with a (high) SAC of .90, with an AL100, 3 minute descent to 110', 2 minutes at 110', then move up to 100' and spend 9 minutes working our way up to 90', a 30'/min ascent to 55' for 1 minute, a 30'/min ascent to 15' for 3 minutes, then surface. Total dive time, 27 minutes, under NDL and I figured I will hit the surface with @ 700 psi, at least according to DivePAL.

Keeping our buoyancy under control shouldn't be a problem - we have spent hours already (literally) practicing, both while diving and educational/training "fun" dives with the LDS.

 

[waterpirate]

Lets talk about the experiance thing and different levels of experiance. Us old guys were around when PADI said we would all die. It was common practice then to dive 1.6 and higher. Some paid a heavy price. A lot of us moved into tech where the stakes got higher so the level of conservancy got ratcheted up some more.

The point is that all of this is just one big experiment. There are alot of varibles to consider, depth, conditions, exertion, level of individual fitness. There is no "straight answer" that can be applied to everyone all the time.

Add to that, who you are listning to. A master ndl diver will have a wildly different take on things than a seasoned techie. So you must choose who you will trust, before you figure it out on your own.

Advice from the tech community looking backwards would be:
If you are on a ndl fun dive with no specific mission other than fun, there is no reason to push anything close to what anybody says the limits are. A po2 of 1.2 to 1.4 will serve you well.
Eric

 

[dwhthediver]

I can't give a specific answer to your question as I just did nitrox recently, and PADI doesn't teach tables anymore... (Though I did learn them, just had to go find them myself.)

However with the zoop, when calculating MOD it has an annoying feature where it adds 1% to the mix you enter. So it reports the MOD at 1.4 PPO2 of EANx32 as 107fsw. This was rather annoyingly confusing until I read the manual and it said it does exactly that.

I still believe the class is good for further understanding.... please take it.

Not to mention it is good for getting nitrox fills, when they ask for your C card.

Actually, that is incorrect, you can order crew packs with tables instead of the ERDPml, even though our store uses the ERDPml, I teach the tables also, because when they take EAN they will know how to use tables, and be ahead of the curve.

 

[Tyger]

Actually, that is incorrect, you can order crew packs with tables instead of the ERDPml, even though our store uses the ERDPml, I teach the tables also, because when they take EAN they will know how to use tables, and be ahead of the curve.

Both the of the local dive shops I've been to here don't carry the table crew packs for EANX. Myself, my fiancee, and the instructor all double checked with the staff about it. (The other dive shop we didn't do the lessons at doesn't even carry tables for the OW crew packs, they just teach computers.) One of them gave the excuse that was all that is taught anymore, with the implication the others aren't available, which is where I got that impression from.

However, on Sunday I was at the LDS I usually go to and spotted a couple EANx table slates for sale loose, so I happily snagged a set. That did make me question the impression I was given about their non-availability, even before seeing your post.

 

[beaverdivers]

Both the of the local dive shops I've been to here don't carry the table crew packs for EANX. Myself, my fiancee, and the instructor all double checked with the staff about it. (The other dive shop we didn't do the lessons at doesn't even carry tables for the OW crew packs, they just teach computers.) One of them gave the excuse that was all that is taught anymore, with the implication the others aren't available, which is where I got that impression from.

However, on Sunday I was at the LDS I usually go to and spotted a couple EANx table slates for sale loose, so I happily snagged a set. That did make me question the impression I was given about their non-availability, even before seeing your post.

Tyger,

Have you tried to buy a typewriter lately?

 

[waterpirate]

Dive gear express also had a pretty good selection of plastic card tables for nitrox.
Eric

 

[beaverdivers]

But, will they work in the winter?

 

[rhwestfall]

But, will they work in the winter?

better than some battery powered POS e-r(crap).... and yes, in winter, and in a pinch, you can scrape your windshield with them too, so they are even more utilitatian. Tables serve a wonderful place as a planning tool... either air tables coupled with EAD calculations/table or tables for popular mixes. They have never let me down....