Wanna stay down longgerrr

[Blackcrusader]

@Edward3c
Sorry I should have given more details.

My normal SAC is just under 15l/m. I did a SAC test finning flat out for 5mins each way and got 20l/m.
So I entered a working SAC of 30l/m and deco of 20l/m in Multideco, so there's a reserve there.
Then I times the planned gas consumption by 1.5 then use that figure to make sure I have at least that available gas.
I've only just completed my Advanced Nitrox/Helitrox deco course so I'm open to other ideas.

Cheers, Mike

But you also dive in cold waters yes? Not the lovely 28c water temp I dive in. I'm fine without a wetsuit to 24c. From 19c to 24c I would wear a wetsuit. Don't want to dive in anything too cold lol.

 

[Manatee Diver]

My normal SAC is just under 15l/m.
I did a SAC test finning flat out for 5mins each way and got 20l/m.
So I entered a working SAC of 30l/m and deco of 20l/m in Multideco, so there's a reserve there.
Then I times the planned gas consumption by 1.5 then use that figure to make sure I have at least that available gas.

I'm pretty similar, my normal tech equipped SAC is about 14-15L/M (0.5cuft/min), but I plan for 20L/M (0.7cuft/min) for both consumption and min gas.

 

[Blackcrusader]

I never, ever managed to have a SAC rate below 11 liters/ minute. My average value is 13. It is still less than other buddies, who are usually around 15 liters/min
A SAC rate of 10 liters/min is really small. It is feasibile perhaps by a very minute lady. My wife is around 11 liters/minute, and she is always the one with more air at the end... Said that, I also do not make complex calculations based on SAC for planning the dive.
What I do instead is to check the SPG very frequently, as I know that different conditions (water temperature, current, activity done) can easily make it double or more. So, when the remaining pressure is not high enough, then it is time to come back, even if the "planned" time has not be reached. On the other side, if everything goes smooth and everyone has plenty of air, I do not have any problem extending the dive by 10 minutes or so, even if this causes some deco obligation. I simply do not care of the NDL. I always start the dive with the plan that, if everything goes well, there wiil be deco stops...

Being Deco trained I can understand you and your wife doing some unplanned deco by say 10 mins and adding a deco stop to a dive. For me I am diving in PADI centers where the vacation divers are not allowed to exceed NDL and many centers want divers to start ascending when they get to 5 mins to NDL. I had one occasion I was with a visiting Instructor with CMAS certs. Her strobes were malfunctioning and as a photographer I could use my video lights for her close up photos. So the DM wants to show her where some special pygmy seahorses are on a coral fan. So by the time we get to the area we are low time to NDL. She decides she wants those photos it's her last dive of her vacation. We end up exceeding NDL by ten minutes at 33m before we head to clear deco obligations. These are at shallow depths so air is not an issue. Of course other divers know we cannot have been there that long without exceeding NDL. As I am her dive buddy I stayed with her. Should I have left her and ascended? maybe. Maybe I should have ascended to depth where I did not exceed NDL and waited for her. She had a small dive torch and would probably have stayed taking photos with that. So as we are coming up I signal to the DM guide we are going to safety stop levels. He knows what I want to do is clear that deco before the other divers join us. For me I was not going to abandon my assigned dive buddy. So I took some photos as well, naughty me.

So yes we both had sufficient air reserves for both divers to share a tank and complete the deco at 6m if an emergency arose. Back on the boat I wasn't too happy and let the instructor know. She was like well I am CMAS and you BSAC and good on air so who cares about PADI dive rules. I'm like well we are on a recreational dive with NDL limits not an unplanned deco dive.

 

[Edward3c]

@Edward3c
Sorry I should have given more details.

My normal SAC is just under 15l/m.
I did a SAC test finning flat out for 5mins each way and got 20l/m.
So I entered a working SAC of 30l/m and deco of 20l/m in Multideco, so there's a reserve there.
Then I times the planned gas consumption by 1.5 then use that figure to make sure I have at least that available gas.

I've only just completed my Advanced Nitrox/Helitrox deco course so I'm open to other ideas.

Cheers, Mike

I didn’t make the point clear enough in post 127, my fault.

The reason for the reserve is not for you, but your buddy. If they loose their gas supply at the worst moment. Calculating purely on what you think you might need could result in not having enough gas in an emergency. It’s been known for a panicked diver to ‘beat the reg’, i.e. demanding gas quicker than the reg can deliver, say 50Lt/min. Put two divers breathing off one 1st stage and the probability of beating the reg is increased.

 

[Mike1967]

The reason for the reserve is not for you, but your buddy.

Yeah the higher SAC rates in the calculations is my reserve and the x1.5 is for my buddy

 

[Mike1967]

I plan for 20L/M

I probably would too but the other guy doing the course got 33l/p on his SAC test

 

[Angelo Farina]

Being Deco trained I can understand you and your wife doing some unplanned deco by say 10 mins and adding a deco stop to a dive. For me I am diving in PADI centers where the vacation divers are not allowed to exceed NDL and many centers want divers to start ascending when they get to 5 mins to NDL. I had one occasion I was with a visiting Instructor with CMAS certs. Her strobes were malfunctioning and as a photographer I could use my video lights for her close up photos. So the DM wants to show her where some special pygmy seahorses are on a coral fan. So by the time we get to the area we are low time to NDL. She decides she wants those photos it's her last dive of her vacation. We end up exceeding NDL by ten minutes at 33m before we head to clear deco obligations. These are at shallow depths so air is not an issue. Of course other divers know we cannot have been there that long without exceeding NDL. As I am her dive buddy I stayed with her. Should I have left her and ascended? maybe. Maybe I should have ascended to depth where I did not exceed NDL and waited for her. She had a small dive torch and would probably have stayed taking photos with that. So as we are coming up I signal to the DM guide we are going to safety stop levels. He knows what I want to do is clear that deco before the other divers join us. For me I was not going to abandon my assigned dive buddy. So I took some photos as well, naughty me.

So yes we both had sufficient air reserves for both divers to share a tank and complete the deco at 6m if an emergency arose. Back on the boat I wasn't too happy and let the instructor know. She was like well I am CMAS and you BSAC and good on air so who cares about PADI dive rules. I'm like well we are on a recreational dive with NDL limits not an unplanned deco dive.

In my opinion you did well staying with your buddy and going into deco range. No reason for feeling uncomfortable thereafter. It still was a normal recreational dive. You did nothing really dangerous, nor "forbidden".
That's why we ALWAYS plan to have deco. "unplanned deco" is an oxymora for me... Deco is always planned - for every dive. That's simple! Then if, for any reason, the dive is shorter, or less deep, then it will become a no-deco dive. But you should always start a dive, ANY dive, prepared to do some deco, if required.
That's the reason for which my standard (minimum) tank size is a 15 liters steel at 232 bar. I really do not understand people diving those crap AL80 small tanks, there is simply not enough air for me for "feeling safe"...

 

[Blackcrusader]

In my opinion you did well staying with your buddy and going into deco range. No reason for feeling uncomfortable thereafter. It still was a normal recreational dive. You did nothing really dangerous, nor "forbidden". That's why we ALWAYS plan to have deco. "unplanned deco" is an oxymora for me... Deco is always planned - for every dive. That's simple! Then if, for any reason, the dive is shorter, or less deep, then it will become a no-deco dive. But you should always start a dive, ANY dive, prepared to do some deco, if required. That's the reason for which my standard (minimum) tank size is a 15 liters steel at 232 bar. I really do not understand people diving those crap AL80 small tanks, there is simply not enough air for me for "feeling safe"...

I didn't feel it was dangerous. Thing is you have other divers who are not so experienced, one DM with some recently certified AOW divers on the same dive at a shallower depth. It sets a bad example when other divers do things when we are supposed to be doing dives and not exceeding NDL. Not forbidden under any law either but some dive centers owners would not be happy about it either. The owner of the dive center I was with is a friend and he wants divers to stick to not exceed NDL on the dives unless it's pre planned and approved as a deco dive.

If I ever get the pleasure to dive with you it would be on the understanding there may well be some deco dive involved even if not pre planned.

 

[Edward3c]

Being Deco trained I can understand you and your wife doing some unplanned deco by say 10 mins and adding a deco stop to a dive. For me I am diving in PADI centers where the vacation divers are not allowed to exceed NDL and many centers want divers to start ascending when they get to 5 mins to NDL. I had one occasion I was with a visiting Instructor with CMAS certs. Her strobes were malfunctioning and as a photographer I could use my video lights for her close up photos. So the DM wants to show her where some special pygmy seahorses are on a coral fan. So by the time we get to the area we are low time to NDL. She decides she wants those photos it's her last dive of her vacation. We end up exceeding NDL by ten minutes at 33m before we head to clear deco obligations. These are at shallow depths so air is not an issue. Of course other divers know we cannot have been there that long without exceeding NDL. As I am her dive buddy I stayed with her. Should I have left her and ascended? maybe. Maybe I should have ascended to depth where I did not exceed NDL and waited for her. She had a small dive torch and would probably have stayed taking photos with that. So as we are coming up I signal to the DM guide we are going to safety stop levels. He knows what I want to do is clear that deco before the other divers join us. For me I was not going to abandon my assigned dive buddy. So I took some photos as well, naughty me.

So yes we both had sufficient air reserves for both divers to share a tank and complete the deco at 6m if an emergency arose. Back on the boat I wasn't too happy and let the instructor know. She was like well I am CMAS and you BSAC and good on air so who cares about PADI dive rules. I'm like well we are on a recreational dive with NDL limits not an unplanned deco dive.

I've done dives requiring mandatory deco whilst on holiday. I’ve always been open with the operator and other clients that both myself and buddy were adequately trained and experienced. When an operator has been clear they don’t want us to enter mandatory deco I comply, this has been the exception.

To do dives with mandatory deco without informing, and getting consent of, the operator is IMHO discourteous and reflects badly on the industry.

 

[Blackcrusader]

I've done dives requiring mandatory deco whilst on holiday. I’ve always been open with the operator and other clients that both myself and buddy were adequately trained and experienced. When an operator has been clear they don’t want us to enter mandatory deco I comply, this has been the exception.

To do dives with mandatory deco without informing, and getting consent of, the operator is IMHO discourteous and reflects badly on the industry.

Yes especially when a visiting instructor from Europe decides to ignore the policy of the dive center in Asia. It was also unplanned deco just decided at the time to exceed NDL She was there several days diving with me so she knew she just decided well last dive it's not like the dive center will stop her diving again. I was with her and another regular dive buddy also a PADI instructor. He did not go into deco. Also what can a DM do when a diver refused to ascend and they have others to take make sure they do not get near DECO? Sometimes I find visiting instructors just want to do as they please and the rules don't apply to them.

I don't ask for DECO dives when diving in a PADI vacation place. I respect their dive center rules.