How I almost drowned -- twice

[billt4sf]

Was 1000 a surprise or did you expect to see roughly that value when you looked then? In retrospect, was the dive plan reasonable (assuming no unexpected crazy currents) given your typical SAC? How much reserve did you expect to have when you got to the deploy SMB stage? Was that enough given the currents that were described?

The other thought is that when you start thinking "I'm not happy doing this, maybe I shouldn't keep going?" you can stop and go back somewhere where you feel you safer/better. You should (when reasonably practical - if you are feeling uncomfortable because the guide just swam off like a bat out of hell...) tell your buddy or guide that you are not going any further so they don't start searching for you. If nobody is paying you to dive then you don't have to do things that are not fun.

Good questions. The 1000 was not a huge surprise, I had been monitoring my air a I always do but it indicated to me what I already knew -- I was stressed and therefore using air fast.

Your questions make me realize that I really need to get a better handle on gas planning. I do not know my SAC rate. I need to get on that. I am embarrassed to admit that. Lacking that I only have gut feel to go on when planning a dive and that sucks big-time. My gut feel was that the dive plan was stretching it a bit to go to 90 feet at the start but I said nothing for various reasons. I am being honest about my inadequacies here.

Regarding swimming horizontally in up and down currents: I had no thought that I was in a up or down current. All I knew was that my depth was changing wildly for no apparent reason. It was just "Oh! my ears!" followed seemingly immediately by "what the H am I doing at 20 feet?!". Then repeat.

Had anyone known what would happen on this dive -- NONE of us would ever have gone.

- Bill

 

[CuzzA]

Putting myself in your shoes and thinking about the experience, I can't really think of anything you did wrong. It happened to everyone so it's not like it was just your error. You survived and that's what matters, but as you said you came close to being OOA during the ordeal. Perhaps, when you realized you were at 20 ft you should of beelined anyway possible to the surface rather than risk the down current taking you further down to the point you may never have been able to return. Obviously I'd rather risk a rapid accent than a uncontrollable descent with no air. Other than that, perhaps a pony bottle should be considered part of your standard rig. I recently made the decision to carry a pony for any dive. There's just too many scenarios I can think of where not carrying one could kill me

Is it common to be able to rent pony bottles on these exotic dive trips? I'm curious to know if I can dive the same way I do at home when I'm on vacation.

 

[billt4sf]

Putting myself in your shoes and thinking about the experience, I can't really think of anything you did wrong. It happened to everyone so it's not like it was just your error. You survived and that's what matters, but as you said you came close to being OOA during the ordeal. Perhaps, when you realized you were at 20 ft you should of beelined anyway possible to the surface rather than risk the down current taking you further down to the point you may never have been able to return. Obviously I'd rather risk a rapid accent than a uncontrollable descent with no air. Other than that, perhaps a pony bottle should be considered part of your standard rig. I recently made the decision to carry a pony for any dive. There's just too many scenarios I can think of where not carrying one could kill me

Is it common to be able to rent pony bottles on these exotic dive trips? I'm curious to know if I can dive the same way I do at home when I'm on vacation.

Pony bottle? Maybe so. But my first step is going to be getting a really solid handle on gas planning and my own SAC. I need to be in a position where I know what dives I can and can't do, rather than relying on a DM that may or may not have the same set of expectations for me that I do.

- Bill

 

[bowlofpetunias]

Excellent to see that you are recognizing some things that you need to work on. You are right about gas planning and knowing what your SAC rates are. Notice I said plural .. SAC rates do change depending on depth and comfort levels on given types of dives. Knowing what your worst rate is likely to be and working based on that is fundamental. I've never seen pony bottles available at the remote sites we have been to.

IMHO it is better to plan your dive with a reserve in your main system and not rely on a pony.

 

[hupe]

Notice I said plural .. SAC rates do change depending on depth

why should the SAC rate change on depth?

 

[bowlofpetunias]

Several reasons. There is the potential of the diver feeling more emotionally stressed. Diver has more Atmospheres of pressure to work against. It is more likely to be colder at depth. Of course we were taught that gas is more compressed at depth. Boyle's Law

 

[Basking Ridge Diver]

why should the SAC rate change on depth?

The only thing I would add - is what type of dive are you doing at depth - on a drift dive SAC / RMV should be low but if you are working in current or pushing to see more of the reef or wreck you will notice your RMV changes with the effort exerted.
If I am playing at 20 feet and just having fun staying in a localized area or shooting some video - my RMV is phenomenal but if I am at depth 70 feet or greater hunting for lobsters or working on the dive - my RMV is higher. So it is not the depth as much as the effort you are exerting on the dive that seems to make the difference.
That said - if you are apprehensive about the dive your RMV will also go up - if you are new to the dive area - nervous about the dive for any reason (depth, current, navigation, dive buddy) - you will also notice an uptick in RMV. I try to track each of my dives and I make notes as to why my SAC / RMV may have been better or worse than my average.
I use this information to make a better judgement on my next similar dive.

 

[CuzzA]

IMHO it is better to plan your dive with a reserve in your main system and not rely on a pony.

Of course planning your dive is important, but it's the unexpected things that you can't plan for or the things that could happen that you simply don't have any control over.

Considering air is the most important thing during scuba diving, I think it's prudent when taking on a challenging dive to plan for that and a redundant air source may make the difference between life or death.

In the OP's scenario there's no way to predict "exactly" how those currents may effect a diver. Even if he planned more conservatively a down current ripping to an unexpected depth could have wiped out any of the conservative measures that were taken. Carrying a pony bottle that's not part of the plan could give you back what was taken by the unexpected incident and save your life. So to write off a pony bottle as not or less of a reliable option doesn't make sense to me. Especially considering how inexpensive it can be to put one together.

 

[Wingy]

Bill, sorry you got to meet the Indonesian Throughflow - I thought I sent you that link, if not I apologise and suggest you may find it worth reading. I know exactly the sweetlips spot at Kri you are talking about from my last trip there a few months ago when the current was actually rather benign on that dive but the afternoon dive that day which I couldn't dive that day after my second ever underwater migraine coming on at Mayhem a couple of hours later the current was ripping and reef hooks were out. Chicken the day before was a thrill a minute express ride too - its an area subject to currents that can change in a second due to the throughflow.

I am not a dive professional just an average diver with a little bit of experience in the area and have had my Ehhhh whats going on here moment in a downcurrent that took me to 43m then an upwelling that spat me back to 7m in seconds and then back down again so I do understand that it is a terrifying experience and when the current changes are rapid as they are it is WTH is happening..i happens before you process it which is the part that makes our hearts race and of course our breathing rate go up. Some places they are known - My personal experience with this sort of current was a spot in N Sulawesi Batu Gosoh. You don't have warning to sort yourself out so it is that horrible dawning that you are completely at the mercy of the ocean. Learning to handle that - and you have experienced it now so thats a big start - wont stop it ever happening again but I suspect you may recognise whats going on and remember you survived it this time. It may never happen again, to either of us, I hope so, but theres no guarantee - the ocean does what it wants.

I will be completely honest and say No I didnt have time to swim across the current and inflate and do this or that because it happened in seconds and was one helluva shock....i was having a lovely dive until that moment. How did I deal with it.....survival instinct kicked in and I crabbed up the wall like..and I apologise to anything I squished and any coral I killed but that was the only thing I could do.

To the best of my recollection I have never seen a pony bottle being used by a diver on a liveaboard over in the neighbourhood.

No dive plan could have countered in this, it suprised and caught the dive guides too if i read your OP properly. Dampier Strait currents are tricky and can turn up down sideways in seconds - the guides cant know that before they descend. Id bet your dive guide was as shocked as you were and the stress of having divers in trouble while he was also in trouble is a testament to his skills and hes probably thinking the same as you are....phewww that one was close.

ETA Tippytoes - the sweetlips gang at Cape Kri are a regular highlight so I'd hazard a guess that particular dive has been done by almost every LOB that plies those waters -

https://www.google.com.au/search?q=...b7lA2IQ_AUIBygC&dpr=1.1#imgrc=SKmsASa8j2JMdM:

Glad all worked out well in the end, take pride in that and learn from that that no amount of skills practicing or fundies or training is going to guarantee the ocean isnt going to decide to give you a reminder of our fragility down there.

If you would like I can send the Flowthrough information through to you again. Good on you for getting back in the water.

 

[billt4sf]

Bill, sorry you got to meet the Indonesian Throughflow - I thought I sent you that link, if not I apologise and suggest you may find it worth reading. I know exactly the sweetlips spot at Kri you are talking about from my last trip there a few months ago when the current was actually rather benign on that dive but the afternoon dive that day which I couldn't dive that day after my second ever underwater migraine coming on at Mayhem a couple of hours later the current was ripping and reef hooks were out. Chicken the day before was a thrill a minute express ride too - its an area subject to currents that can change in a second due to the throughflow.

I am not a dive professional just an average diver with a little bit of experience in the area and have had my Ehhhh whats going on here moment in a downcurrent that took me to 43m then an upwelling that spat me back to 7m in seconds and then back down again so I do understand that it is a terrifying experience and when the current changes are rapid as they are it is WTH is happening..i happens before you process it which is the part that makes our hearts race and of course our breathing rate go up. Some places they are known - My personal experience with this sort of current was a spot in N Sulawesi Batu Gosoh. You don't have warning to sort yourself out so it is that horrible dawning that you are completely at the mercy of the ocean. Learning to handle that - and you have experienced it now so thats a big start - wont stop it ever happening again but I suspect you may recognise whats going on and remember you survived it this time. It may never happen again, to either of us, I hope so, but theres no guarantee - the ocean does what it wants.

I will be completely honest and say No I didnt have time to swim across the current and inflate and do this or that because it happened in seconds and was one helluva shock....i was having a lovely dive until that moment. How did I deal with it.....survival instinct kicked in and I crabbed up the wall like..and I apologise to anything I squished and any coral I killed but that was the only thing I could do.

To the best of my recollection I have never seen a pony bottle being used by a diver on a liveaboard over in the neighbourhood.

No dive plan could have countered in this, it suprised and caught the dive guides too if i read your OP properly. Dampier Strait currents are tricky and can turn up down sideways in seconds - the guides cant know that before they descend. Id bet your dive guide was as shocked as you were and the stress of having divers in trouble while he was also in trouble is a testament to his skills and hes probably thinking the same as you are....phewww that one was close.

ETA Tippytoes - the sweetlips gang at Cape Kri are a regular highlight so I'd hazard a guess that particular dive has been done by almost every LOB that plies those waters -

https://www.google.com.au/search?q=...b7lA2IQ_AUIBygC&dpr=1.1#imgrc=SKmsASa8j2JMdM:

Glad all worked out well in the end, take pride in that and learn from that that no amount of skills practicing or fundies or training is going to guarantee the ocean isnt going to decide to give you a reminder of our fragility down there.


If you would like I can send the Flowthrough information through to you again. Good on you for getting back in the water.

Great points Wingy and I have read the Indonesian Throughflow article you sent me several times and have forwarded it as well.

Someone on SB has a signature that reads something like "The Ocean is a poor teacher --- first you get the test, then you get the lesson" and that is sure true. Although yes, I *had* had the "lesson" on swimming horizontally in up and down currents but it is as you described it so well.

Just like since that dive I have been playing out in my mind how relaxed I should be if I had to do a CESA from 100 ft. Yeah, um hm....

- Bill