28% Nitrox

[leabre]

Because it is more conservative I prefer to convert to EAD and use the air table as a reference then plan as if diving on air. Maybe I cheat myself out of some bottom time but I am rewarded with a far more conservative dive and if I happen to want more bottom time during the dive for whatever reason I have that in my back pocket. Take your course from whatever training agency and then read and re-read the Navy Dive Manual (rev6). I have been planning and diving the Navy tables for over thirty years with great success and have never once had a problem. It depends on your motivation for diving Nitrox..... Do you want more bottom time, more margin of safety, more certificates, more math...... only each diver can decide that for him/herself. Just find someone with more experience if you don't understand something.

Since you put it like that, i'll take more math any day

 

[redacted]

Because it is more conservative I prefer to convert to EAD and use the air table as a reference then plan as if diving on air. Maybe I cheat myself out of some bottom time but I am rewarded with a far more conservative dive and if I happen to want more bottom time during the dive for whatever reason I have that in my back pocket. Take your course from whatever training agency and then read and re-read the Navy Dive Manual (rev6). I have been planning and diving the Navy tables for over thirty years with great success and have never once had a problem. It depends on your motivation for diving Nitrox..... Do you want more bottom time, more margin of safety, more certificates, more math...... only each diver can decide that for him/herself. Just find someone with more experience if you don't understand something.

Isn't the idea of EAD being more conservative dependent on the idea of how you handle depth rounding in producing the table and in recording your dive? If you use precise depths rather than rounded depths, you should get the same results.

 

[Blackwood]

But most dive tables only list numbrs in 10' increments (some few have them in 5' increments, but only for very shallow depths IIRC).

I imagine that 90% of the time, you have to round.

 

[String]

Wonder what agency the poster did Nitrox with. Ive got a feeling it might be one of the new "computer" ones be it SSI or PADI which now has all the theory and concepts stripped out of it. Sadly its quite possible now to have a diver on nitrox with no idea what EAD is (other than BSAC divers who aren't taught it!).
A lazy instructor teaching to the minimums and standards can easily lead to students who don't know these things.

 

[James228]

PADI's new book completely took the whole last chapter out of the Nitrox book and off the test compared to older ones I have seen.

 

[String]

You mean what we refer to as the "nitrox leaflet" now.

 

[redacted]

You may already have a table that will work as well as any of the pre-made tables for recreational nitrox in terms of tracking nitrogen loading and NDLs. Take any table (or all if you would like more "depth" points) and convert depth in feet or meter to partial pressure of nitrogen. Of course, you must also convert your planned and actual recorded depths to the same units for the gas you are breathing and you are in business.

Anybody have a headache?


BTW, just a word of caution. I have not done this yet myself. If you dive with a computer life is much easier. But I did notice my PADI EAD table did not cover the specific question of 28% so I got to thinking.... And this is what happened. I'm pretty confident it is correct.

 

[scubadada]

.......U-853 in RI mix.............Morehead City wrecks mix..............Florida Keys wrecks (Spiegel, Duane, Bibb, Eagle, Vandy) mix..............

I dive 32% on the Speigel Grove and the Duane and generally limit my max depth to 110 ft.

Good diving, Craig

 

[VooDooGasMan]

My thought was some diver is learning, when I seen 28%. I actually topped off years ago and used the lower % at a deeper dive till I got to air (21%). So lds cost for fill was 40%, 4 beachaut 140 would enable me to fast fill and top off, the 28% was a deeper nitrox dive and could have many fills from a 140 cf cascade system. I currently have 75%in them for filling deco tanks in them now.

Spearfishing is great fun at depth, so 28% was a good % I established, now I see others dive it also in florida and new jersey wrecks. 25 26 27% was what some ended up on quick fills, which were fine also for deeper spearfishing.



Happy Diving

 

[krawlings]

28% is not in the PADI dive tables bacause that puts a diver beyond the 130' max depth for a rec diver