Beyond 130 feet: always a deco dive?

[Dive Bug Bit Me]

Sorry for the hijack, but I've never seen anyone do that. Why?

I suspect there's so much rounding involved in the forcing of even 10 foot or 3 meter intervals and whole minute schedules that a foot and a few seconds here or there is largely meaningless.

Cause when I do choose to do a computer based deco profile if I am one inch above the stop for 60 seconds, my computer will refer me to tables (some of my computers will lock me out). Therefore to keep the computer alive, I do the rounding by being a touch below the stop.

 

[Blackwood]

Cause when I do choose to do a computer based deco profile if I am one inch above the stop for 60 seconds, my computer will refer me to tables. Therefore to keep it content, I do the rounding by being a touch below the stop.

Lol fair enough. Knew there had to be.a practical reason.

 

[cbrich]

From a deco perspective that makes very little sense.
Shallower stops are always going to be longer than deeper ones. Doing deco on air at 20 feet will take longer than it would at 10 feet.
My guess is the safety stop depth is set at 15 feet so the computer decides deco stops need to be deeper ??

Safety stops are optional,not mandatory. What is the status of a safety stop after a deco stop? i.e. is it really a safety stop or a deco stop??

I suspect, the manufacturer set the last deco stop to 20', (I can think of several reasons but that is for some other time,) so they can put their safety stop in there too.

In my computer I have the choice to set my last stop at 10' or 20', but then again it's not the typical recreational dive computer . I have it set to 10' but usually opt to stay at 20' or go to 15'.

In the PADI/DSAT Tec courses, a safety stop was never mandatory, but it was optional. If your last stop was at 10', then you extend that stop by 3 minutes. But this is not to be confused with Deep Stops, PADI/DSAT always recommended deep stops, 1/2 way between your bottom depth, and first deco stop for 1 minute.

I don't know of an agency that recommends using a computer only in technical diving. I remember doing a lot of planning, and cutting tables for my dives in the PADI/DSAT. Our tables were always more conservative than the computers, because we typically did not stay at the bottom depth for the entire time, so the computer always showed a shorter deco times. However, if something happened where your computer exceed your table, then you had to clear your computer.

---------- Post Merged at 10:13 AM ---------- Previous Post was at 10:10 AM ----------

Cause when I do choose to do a computer based deco profile if I am one inch above the stop for 60 seconds, my computer will refer me to tables (some of my computers will lock me out). Therefore to keep the computer alive, I do the rounding by being a touch below the stop.

I know of 1 computer that has said "refer to tables," if the diver blew a stop, if I owned that computer, I would sell immediately after that dive. Typically a dive computer should be the backup to your tables in technical diving.

 

[James R]

Cause when I do choose to do a computer based deco profile if I am one inch above the stop for 60 seconds, my computer will refer me to tables (some of my computers will lock me out). Therefore to keep the computer alive, I do the rounding by being a touch below the stop.

I don't know of any computer that will tell you that you're an inch above your stop depth. If you are a foot (or more) above it without noticing it for 60sec then you (in my opinion anyway) are not paying attention to what you're doing very well.

At that point would you move to your missed stop plan & procedures or continue on as you were?

Also, what computer are you using?

 

[Dive Bug Bit Me]

I don't know of any computer that will tell you that you're an inch above your stop depth. If you are a foot (or more) above it without noticing it for 60sec then you (in my opinion anyway) are not paying attention to what you're doing very well.

At that point would you move to your missed stop plan & procedures or continue on as you were?

Also, what computer are you using?

I dive in metric, so it actually takes 10cm to cause a problem. That's about 4 inches.
No in practice, I am not going to move to missed stop plans for 4 inches.

Not sure what you use to deco. If your computer is set to feet, remember that it rounds off, so in reality a move of a tiny amount can cause it to read one foot different. You are not holding it exactly on the intended depth without ticking up or down for a meaningful deco stop.

Deco using a VR as primary. It will flash a lot of warnings, but stick with me for the rest of the deco if I miss one of the stops. Actually find it great as a deco computer.

 

[chrpai]

In the PADI/DSAT Tec courses, a safety stop was never mandatory, but it was optional.

I haven't taken PADI Tec courses. I guess they aren't required because you've done other stops.

In a recreational dive plan, the PADI/DSAT RDP instructions are:

Safety Stops - A safety stop for 3 minutes at 15ft is required any time the diver compes up to or within 3 pressure groups of a no de-compression limit and for any dive to a depth of 100ft or deeper.

 

[DevonDiver]

TecRec, as with many other agencies, suggest that the technical diver can 'pad out' their final deco stop, if they want to. In essence, it is a safety stop - a non-mandatory period of desaturation at the shallowest stop depth, for the purpose of voluntary additional conservatism in ascent.

 

[James R]

I dive in metric, so it actually takes 10cm to cause a problem. That's about 4 inches.
No in practice, I am not going to move to missed stop plans for 4 inches.

Not sure what you use to deco. If your computer is set to feet, remember that it rounds off, so in reality a move of a tiny amount can cause it to read one foot different. You are not holding it exactly on the intended depth without ticking up or down for a meaningful deco stop.

Deco using a VR as primary. It will flash a lot of warnings, but stick with me for the rest of the deco if I miss one of the stops. Actually find it great as a deco computer.

4 inches definitely doesn't give you a lot of room for error, I agree for sure.

I cut tables for technical dives in GAP so my computer is considered backup to them. I plan to never end a dive until I have completed the run schedule according to those tables and cleared my computer just to add a little more conservatism to the dive plan. My computer has never had remaining deco after the table schedule has completed, which is due to how I cut the plan in GAP (more conservative). Computer is a Uwatec Galileo Luna w/multi-gas capability.

 

[cbrich]

I see that now, and I don't blame PADI for putting that on it. In the DSAT programs there are NO PADI Tec dive tables, or little calculator. They put that on there, so that material meets PADI's legal requirements. It's up to the diver's responsibility whether they follow what they were taught. There is no such thing as the PADI popo (police), but there is something called Judgement and you have to use it on every dive.

 

[DevonDiver]

I see that now, and I don't blame PADI for putting that on it. In the DSAT programs there are NO PADI Tec dive tables, or little calculator. They put that on there, so that material meets PADI's legal requirements. It's up to the diver's responsibility whether they follow what they were taught. There is no such thing as the PADI popo (police), but there is something called Judgement and you have to use it on every dive.

To be honest, it's not a PADI 'initiative'... the concept of padding your deco is hardly exclusive.. or new...