One great clarification that came in for this video is when I mentioned "keep breathing" in concerns to preventing lung over expansion as you ascend, I should clarify that the goal of this is to breath in slowly if needed but mostly exhale, especially if your are rapidly ascending it might be better to keep the lungs mostly empty. Over expansion occurs as the air in the lungs expand so less air in the lungs is good in this case.
One clarification to suggest: when you say "keep breathing" during a controlled emergency swimming ascent, what you really mean is "keep exhaling". The air in your lungs will expand continuously as you ascend, and you need to keep exhaling (not inhaling) throughout the ascent to prevent an overexpansion injury.
Great call out and I totally agree with you, even if you keep breathing but take a giant breath in one can be in for a world of hurt. I do speak to this topic in some other videos I am scripting so will try to clarify this better in the future!
Great advice all. This type of video is really useful; it gets divers thinking about what they might do if they have a problem. And I'd say that's something you should actually do on every dive. Just every now and then think about where you are, where your buddy is and what you'd do if an O-ring blew or an inflator jammed or whatever. And yes, practice drills with your buddy when you get the chance. The skills do fade. On the controlled swimming ascent and EBA, I have a little experience. I did the sub escape course many years ago, which involved swimming up from 100ft with basically just a bag over your head. I almost could not breathe out fast enough and certainly could not have taken a breath in! A Scuba EBA is a little slower maybe but it's still around a minute from 100ft. Even when you're stressed a fit person should be able to hold their breath that long and in an ascent it's easier because you don't feel that tightness in your chess you feel on land; your lungs are fuller than is comfortable and you are just having a long breath out. It feels great! On ditching weights, yes a last resort. Most tech divers do not have ditchable weight. What they do have is exactly the right amount to get back up safely, and stop on the way as required. I'm sure you'll agree that getting in with the correct weighting is a great safety measure, and it reduces air consumption. Win-win!
Definitely hear the experience coming from you and appreciate your thoughts here! A submarine escape course sounds pretty exhilarating, guessing for military purposes? Totally agree with you that proper weighting is crucial for getting back to the surface in event of a BCD failure! I know as a tech diver; you'd also be able to utilize the dry suit too to control buoyancy in event of system failure, but we know how squirrely that thing could be. I tend to dive without ditchable weight as well, I go with as little as possible! I have found too because my wife and I do exercise and hit the gym regularly, we are fairly dense and heavy people, so we tend to need less weight even in cold water.
I actually witnessed my dive buddy drown in front of me back when I was 17 he was 19. We were deep and got separated from the group and he was a bit reckless.
Thank you for sharing, that's a truly hard situation for anyone to recover from. Scuba diving can be quite dangerous which is why I hope we can all aspire to be safer and help keep the sport fun and safe as possible.
As usual, a reasonably good explanation, but the slightly more advanced tips are missing. The most important one is don't just check if you have enough, you could check if the reading makes sense. I was thought, in my very first diving course, to first estimate what the gauge should read, and only then check it. Assuming a single 12L tank and a reasonable gas consumption of 20L/min at the surface, that is almost 2 bar per minute, times the pressure at depth. So if you're at 15m, you should consume about 5 bar per minute. If you last checked 5 minutes ago, the gauge should read about 25 bar lower. This means you need to remember what it was the last time you checked. Usually, you will find that you have a little more than you calculated, but not too much. If you're still reading 200 bar 30 minutes into the dive, while you started at just over 200 bar, something is wrong. The gauge may be stuck, or your isolator valve is closed, if you dive doubles. It's all about awareness. Learn to sense when something doesn't add up, and don't dismiss it. Also, if you're diving to 40m, you really should be diving doubles, since the minimum gas you would need in a single tank for a 2 diver controlled ascent from 40 meters is 160 bar; by the time you get there, you have to leave. Minimum gas calculation: From 40 meters, at a controlled 3 m/min takes 14 minutes, with 2 divers each consuming 20L/min, at an average pressure of 3 bar, is 1680L of gas. Add one minute at 40m to manage the out of gas emergency, and calm down a little, that's another 200L. (1680L + 200L) / 12L ~= 160 bar.
Thank you for the great and thoughtful response and super valuable for others! I love the tip for calculating your consumption rate! I did mention this tip in the recent 25 tip video, but yes, that would have been a good one for this video, too! I do agree it's a great habit to be able to have a good idea and project how much will be used to train the intuition. The main goal is, as you said, to be able to understand consumption deeply, catch things when they aren't matching the projections, and also less likely to be caught off guard. I agree with you that 40 m is safer with doubles, and you have a great minimum gas calculation for the dive plan. I will say the ascent profile in your projection is a bit conservative as I know PADI mentions you can ascend at 18 m per minute which is super fast, but I know most divers use 10 m per minute up to safety stop. GUE teaches cut the maximum depth in half and ascend at 9 m per minute up to half, then hover for 30 seconds and then raise by 3 meter over 30 seconds, so 3 meter per minute up to the surface so that's 8 minutes to the top. Regardless, it's a great point, and I do agree with you that most risks under 30 meters to 40ish meters are significantly reduced with doubles. I'm still not doing doubles yet myself but I do plan to buy the gear setup early next year as I do agree it's generally safer, and I like the idea of improved balance. At least when we are diving near our home. We do a lot of travel diving, too, so single tank diving can't be avoided always.
One tip is missing in my humble opinion, train those emergency procedures! Take time in a pool or plan the last 5 minutes of a dive to do air sharing or any emergency procedure. If you don't train, how are you going to react when it happens? By training you retain and reaffirm those procedures and build muscle memory to execute them promptly. I once ran out of air at 18 meters due to a fault of my own. Long story short, went diving with someone with a DPV, didn't turn my backup regulator around so due to prop wash it freeflowed whenever we were scootering (I was being towed by my buddy). Lost 4800 liters of air in 10 minutes so yes, it can go very quickly. As we had trained, once I signalled out of air, we quickyl shared air and ascended safely.
This is great advice, I am a fan of practice drills, and they don't take too long and can be done at the start or end of a dive regularly. I do know a group of divers that practice in such a way that to keep each other on their toes, they can throw an emergency drill at each other at any time. Also, thank you for sharing! This is a good learning experience as I am sure most everyone has had at some by sharing these stories it's a more impactful way for others to learn. I do hope to do better with story telling more in future videos. Still trying to improve that aspect of my videos haha.
@itravelwisely I highly recommend the course "Human factors, non-technical skills in diving" by Gareth lock. At the very least do the webinar, it's a game changer
In the Netherlands I hardly go deeper than 10 meters. Mostly at 8 meters. Nothing to see deeper. And at 8 meters nothing really scary could happen. Never ran out of air though. At 100 bar we always return home so we have plenty of time to return without surprises.
Whew, diving in the Netherlands must be cold! I imagine at least above 10 meters it's a touch warmer, haha. I think, for the most part, the thought of running out of air should be more of not that it hasn't happened but that it can and will happen if you dive long enough. Maybe not your fault. It could be a gear failure and could be someone else in the group, but that's how I like to think. That way, there are no surprises or drama around when it does happen. It's just a part of the diving experience.
@ depends when you go diving. In summer it's around 20 degrees celcius. Now it's around 12 degrees celcius. In summer you really need a 7mm wetsuit or semidry or full dry. I used this summer a 5mm semidry but for me it's was too cold. Also have drysuit but in summer it's sweating my butt off inside. For me I dive with my partner and we are used to each other. So we ask air plenty of times and being 1 pixel 😂. But yea you have to be careful. Mostly we end dive around 80 bar knowing we have plenty of air in case something could happen
I'm glad to hear you are okay! Out of air situations is one of the most dangerous things in scuba diving, but doing drills, practicing, and preparing for not if but when it happens helps turn something that could be devastating into something that your preparedness has mitigated. Something we should all aspire for and practice.
One great clarification that came in for this video is when I mentioned "keep breathing" in concerns to preventing lung over expansion as you ascend, I should clarify that the goal of this is to breath in slowly if needed but mostly exhale, especially if your are rapidly ascending it might be better to keep the lungs mostly empty. Over expansion occurs as the air in the lungs expand so less air in the lungs is good in this case.
One clarification to suggest: when you say "keep breathing" during a controlled emergency swimming ascent, what you really mean is "keep exhaling". The air in your lungs will expand continuously as you ascend, and you need to keep exhaling (not inhaling) throughout the ascent to prevent an overexpansion injury.
Great call out and I totally agree with you, even if you keep breathing but take a giant breath in one can be in for a world of hurt. I do speak to this topic in some other videos I am scripting so will try to clarify this better in the future!
Great advice all. This type of video is really useful; it gets divers thinking about what they might do if they have a problem. And I'd say that's something you should actually do on every dive. Just every now and then think about where you are, where your buddy is and what you'd do if an O-ring blew or an inflator jammed or whatever. And yes, practice drills with your buddy when you get the chance. The skills do fade.
On the controlled swimming ascent and EBA, I have a little experience. I did the sub escape course many years ago, which involved swimming up from 100ft with basically just a bag over your head. I almost could not breathe out fast enough and certainly could not have taken a breath in! A Scuba EBA is a little slower maybe but it's still around a minute from 100ft. Even when you're stressed a fit person should be able to hold their breath that long and in an ascent it's easier because you don't feel that tightness in your chess you feel on land; your lungs are fuller than is comfortable and you are just having a long breath out. It feels great!
On ditching weights, yes a last resort. Most tech divers do not have ditchable weight. What they do have is exactly the right amount to get back up safely, and stop on the way as required. I'm sure you'll agree that getting in with the correct weighting is a great safety measure, and it reduces air consumption. Win-win!
Definitely hear the experience coming from you and appreciate your thoughts here!
A submarine escape course sounds pretty exhilarating, guessing for military purposes?
Totally agree with you that proper weighting is crucial for getting back to the surface in event of a BCD failure! I know as a tech diver; you'd also be able to utilize the dry suit too to control buoyancy in event of system failure, but we know how squirrely that thing could be.
I tend to dive without ditchable weight as well, I go with as little as possible! I have found too because my wife and I do exercise and hit the gym regularly, we are fairly dense and heavy people, so we tend to need less weight even in cold water.
I actually witnessed my dive buddy drown in front of me back when I was 17 he was 19. We were deep and got separated from the group and he was a bit reckless.
Thank you for sharing, that's a truly hard situation for anyone to recover from. Scuba diving can be quite dangerous which is why I hope we can all aspire to be safer and help keep the sport fun and safe as possible.
As usual, a reasonably good explanation, but the slightly more advanced tips are missing.
The most important one is don't just check if you have enough, you could check if the reading makes sense.
I was thought, in my very first diving course, to first estimate what the gauge should read, and only then check it. Assuming a single 12L tank and a reasonable gas consumption of 20L/min at the surface, that is almost 2 bar per minute, times the pressure at depth. So if you're at 15m, you should consume about 5 bar per minute. If you last checked 5 minutes ago, the gauge should read about 25 bar lower. This means you need to remember what it was the last time you checked. Usually, you will find that you have a little more than you calculated, but not too much. If you're still reading 200 bar 30 minutes into the dive, while you started at just over 200 bar, something is wrong. The gauge may be stuck, or your isolator valve is closed, if you dive doubles.
It's all about awareness. Learn to sense when something doesn't add up, and don't dismiss it.
Also, if you're diving to 40m, you really should be diving doubles, since the minimum gas you would need in a single tank for a 2 diver controlled ascent from 40 meters is 160 bar; by the time you get there, you have to leave.
Minimum gas calculation:
From 40 meters, at a controlled 3 m/min takes 14 minutes, with 2 divers each consuming 20L/min, at an average pressure of 3 bar, is 1680L of gas. Add one minute at 40m to manage the out of gas emergency, and calm down a little, that's another 200L.
(1680L + 200L) / 12L ~= 160 bar.
Thank you for the great and thoughtful response and super valuable for others! I love the tip for calculating your consumption rate! I did mention this tip in the recent 25 tip video, but yes, that would have been a good one for this video, too! I do agree it's a great habit to be able to have a good idea and project how much will be used to train the intuition. The main goal is, as you said, to be able to understand consumption deeply, catch things when they aren't matching the projections, and also less likely to be caught off guard.
I agree with you that 40 m is safer with doubles, and you have a great minimum gas calculation for the dive plan. I will say the ascent profile in your projection is a bit conservative as I know PADI mentions you can ascend at 18 m per minute which is super fast, but I know most divers use 10 m per minute up to safety stop. GUE teaches cut the maximum depth in half and ascend at 9 m per minute up to half, then hover for 30 seconds and then raise by 3 meter over 30 seconds, so 3 meter per minute up to the surface so that's 8 minutes to the top. Regardless, it's a great point, and I do agree with you that most risks under 30 meters to 40ish meters are significantly reduced with doubles.
I'm still not doing doubles yet myself but I do plan to buy the gear setup early next year as I do agree it's generally safer, and I like the idea of improved balance. At least when we are diving near our home. We do a lot of travel diving, too, so single tank diving can't be avoided always.
Decent post except the metric nonsense
Very good explanation.
Retired PADI DIVE MASTER
Super appreciate this message and glad you enjoyed it!
One tip is missing in my humble opinion, train those emergency procedures! Take time in a pool or plan the last 5 minutes of a dive to do air sharing or any emergency procedure. If you don't train, how are you going to react when it happens? By training you retain and reaffirm those procedures and build muscle memory to execute them promptly.
I once ran out of air at 18 meters due to a fault of my own. Long story short, went diving with someone with a DPV, didn't turn my backup regulator around so due to prop wash it freeflowed whenever we were scootering (I was being towed by my buddy). Lost 4800 liters of air in 10 minutes so yes, it can go very quickly. As we had trained, once I signalled out of air, we quickyl shared air and ascended safely.
This is great advice, I am a fan of practice drills, and they don't take too long and can be done at the start or end of a dive regularly. I do know a group of divers that practice in such a way that to keep each other on their toes, they can throw an emergency drill at each other at any time.
Also, thank you for sharing! This is a good learning experience as I am sure most everyone has had at some by sharing these stories it's a more impactful way for others to learn.
I do hope to do better with story telling more in future videos. Still trying to improve that aspect of my videos haha.
@itravelwisely I highly recommend the course "Human factors, non-technical skills in diving" by Gareth lock. At the very least do the webinar, it's a game changer
Very cool, and I appreciate the recommendation!
Did a brief look into it and looks up my alley! Will check it out!
Thank you indeed❤
Thank you too!
In the Netherlands I hardly go deeper than 10 meters. Mostly at 8 meters. Nothing to see deeper. And at 8 meters nothing really scary could happen. Never ran out of air though. At 100 bar we always return home so we have plenty of time to return without surprises.
Whew, diving in the Netherlands must be cold! I imagine at least above 10 meters it's a touch warmer, haha.
I think, for the most part, the thought of running out of air should be more of not that it hasn't happened but that it can and will happen if you dive long enough. Maybe not your fault. It could be a gear failure and could be someone else in the group, but that's how I like to think. That way, there are no surprises or drama around when it does happen. It's just a part of the diving experience.
@ depends when you go diving. In summer it's around 20 degrees celcius. Now it's around 12 degrees celcius. In summer you really need a 7mm wetsuit or semidry or full dry. I used this summer a 5mm semidry but for me it's was too cold. Also have drysuit but in summer it's sweating my butt off inside. For me I dive with my partner and we are used to each other. So we ask air plenty of times and being 1 pixel 😂. But yea you have to be careful. Mostly we end dive around 80 bar knowing we have plenty of air in case something could happen
@Richard1976 why would you need 7mm at 20c.thats 68 degrees so comfy water. You'd think you would be acclimated already.
Happened to me. In those days no reserve tanks. Tried to exhale while
ascending. Very scary but if you panicked you die!
I'm glad to hear you are okay! Out of air situations is one of the most dangerous things in scuba diving, but doing drills, practicing, and preparing for not if but when it happens helps turn something that could be devastating into something that your preparedness has mitigated. Something we should all aspire for and practice.