Translating the GUE T/1 Deco Curve

[Rainer]

I think you missed by original post which was directed mostly at new T1 divers. Better to find yourself with extra gas those first few dives than too little.

In any case, I totally agree, that on reef ascents, I end up with TONS of extra deco gas. Sadly, I hardly ever do those. In mid-water, which is cold(ish), and a bit of current, 30 minutes leaves a pretty small reserve in an AL40 (certainly under what I was taught to reserve).

YMMV.

I tend to plan max 25 on a 40 now, and would just bring O2 as well if wanting longer deco times.

I consider a 40 a 30 min bottle and will plan a dive that way. Generally on a reef ascent ending up with 800+ psi and on an ascent up an anchor maybe down to 500.

 

[PfcAJ]

Its important not to overextend yourself on just one bottle. If you really need an 80 of 50%, take a 40 of 50% and a 40 of o2. This will cut your deco and allow more flexibility if something breaks.

On longer dives where you have incorporated two bottles and 40cuft isn't cuttin' it, then upgrade to an al80.

 

[limeyx]

I think you missed by original post which was directed mostly at new T1 divers. Better to find yourself with extra gas those first few dives than too little.

In any case, I totally agree, that on reef ascents, I end up with TONS of extra deco gas. Sadly, I hardly ever do those. In mid-water, which is cold(ish), and a bit of current, 30 minutes leaves a pretty small reserve in an AL40 (certainly under what I was taught to reserve).

YMMV.

I tend to plan max 25 on a 40 now, and would just bring O2 as well if wanting longer deco times.

Yes for sure better to start with 20-25 mins planned deco and work from there.

 

[Sloth]

In Tech 1 Gideon taught us in to just keeping it simple and doing linear RD. I kind of got a vibe that RD shaping was instructor preference. Before class I was doing s-curves mainly because we were doing 2 bottles and the s-curve helps add enough time at 30 to do a switch to back gas. If I am diving one bottle then I like linear, two bottles and I'd probably do an s-curve if the linear profile didnt have much time at 30 for back gas switch and clean up.

Additionally I too was taught the 20ftpm from deep stop to gas switch. Before the class I was doing the older 10ftpm from deep stop to switch. What was weird to me was that Gideon said the ascent rates were still the same 10fpm for Tech 2 dives. I never did get a good answer for the new ascent rate for Tech 1 level dives.