Even though I’m still working towards AOW I really enjoy the analytics of how I personally use my own air and my wife as well, so I track our SAC, RMV, average depth, & max depth on an spreadsheet. It’s helping me find out average consumption, and be able to calculate with rough scuba math if we are going to have to turn a dive earlier due to more current than planned, and if I need to go shallower to surface with sufficient reserve. It’s over the top for the type of diving I’m doing now which is mostly reef dives in Bonaire, but I think it makes me a more aware diver, and will give me a better starting point for tec at some point. Thanks so much for the t-shirt by the way. 👍🏻
Caleb, absolutely nothing wrong with keeping track of your consumption. Definitely helps in the long run in planning dives and it’s nice over time to see how much more efficient you are becoming as a diver as you see your consumption rate decreasing. In our Solo diving series we cover the specifics of how to formally do a SAC rate test. And in an upcoming video we plan to revisit that test with a little different math. :) Thanks for your comments and we are glad you received your shirt!
@@everythingscuba even though I got certified PADI I like the way GUE and ISE work out their minimum gas pressure for any depth. “Just show up to the boat with 500psi left” leaves you with no information as a new diver when to ascend. Looking forward to the new widen in SAC.
Actually, the most common tank in Europe is 12 liter which accounts to 2400 liter air at 200 bar. The recommended reserve is 50 bar, so you have a slightly bigger tank and a reserve of almost 50% more than at 500 psi.
That really depends on your dive profile. Theoretically you would use the same amount of gas whether it's a shallow or a deep dive before and after the turnaround, as long as you stay at the same depth, you don't have to swim back against the current, and you're the only one breathing off of your air supply. Generally speaking, your dive shallows as you return to your point of entry (aiding in off-gassing), and you start your dive going against the current so you can go with the current on the way back. This means you're using less breathing gas on the way back in both scenarios. Splitting it 50/50 already gives you an extra safety margin. In an OOA situation, you end the dive where you are. You don't return to your point of entry underwater in a scenario like that. You do that on the surface.
You should always have an alternate source of breathing gas when you dive. That can be an extra cylinder and/or a buddy. And, of course you also need to regularly check your gauges, and do it consciously. Note your air pressure, and compare your next reading to your previous one. Did you use more than you expected? Check for leaks, shallow up, and/or return sooner. If you didn't use any gas, your SPG is broken. End the dive if you don't have a backup.
The reserve pressure is rounded to an easy to remember number. In the US it's 500 psi, in the rest of the world it's 50 bar. It's not exactly the same value after conversion. The same way in the US the first car service is often at 1000 miles, and in the rest of the world it's at 2000 km (instead of 1600 km, which would be the same after conversion). Also, in the rest of the world, cylinder sizes are measured in physical dimensions, not in maximum capacity. So an Al-80 isn't a 2200 liter, but an 11 liter cylinder. This means it's not immediately obvious when you're comparing cylinders of different sizes and maximum pressures to determine which one will hold the most gas. However, since metric calculations are so much easier to perform than imperial, the maximum capacity can be easily determined by some simple mental arithmetic. Also, you're almost always dealing with cylinders containing less than maximum fill capacity, and denoting a cylinder as 80 cuft would be considered misleading if there's only 68 cuft of air in there. The physical size of 11 liters is true no matter how much pressurized air it contains. The rule of thirds is mostly applicable to diving in overhead environments, because you need enough gas to make it out safely if your buddy runs out of air at the deepest point of penetration. For regular open water diving, very few technical divers will apply the rule of thirds. I recently learned that on penetration dives with DPV's, a rule of fourths is applied when you have a backup DPV, and a rule of sixths if you don't. This is because you cover distance far more quickly with a DPV than you can on your own power. If your DPV fails, you will need to have enough reserve gas to be able to swim back to safety.
Thank you 🌹👌🩵
Even though I’m still working towards AOW I really enjoy the analytics of how I personally use my own air and my wife as well, so I track our SAC, RMV, average depth, & max depth on an spreadsheet. It’s helping me find out average consumption, and be able to calculate with rough scuba math if we are going to have to turn a dive earlier due to more current than planned, and if I need to go shallower to surface with sufficient reserve. It’s over the top for the type of diving I’m doing now which is mostly reef dives in Bonaire, but I think it makes me a more aware diver, and will give me a better starting point for tec at some point. Thanks so much for the t-shirt by the way. 👍🏻
Caleb, absolutely nothing wrong with keeping track of your consumption. Definitely helps in the long run in planning dives and it’s nice over time to see how much more efficient you are becoming as a diver as you see your consumption rate decreasing. In our Solo diving series we cover the specifics of how to formally do a SAC rate test. And in an upcoming video we plan to revisit that test with a little different math. :) Thanks for your comments and we are glad you received your shirt!
@@everythingscuba even though I got certified PADI I like the way GUE and ISE work out their minimum gas pressure for any depth. “Just show up to the boat with 500psi left” leaves you with no information as a new diver when to ascend. Looking forward to the new widen in SAC.
Very good video.
Great video and information. Thanks!
I do the rule of thirds easier to keep count but use something it’s a bad day to run out of gas at depth
Actually, the most common tank in Europe is 12 liter which accounts to 2400 liter air at 200 bar. The recommended reserve is 50 bar, so you have a slightly bigger tank and a reserve of almost 50% more than at 500 psi.
Thanks Leopold. Appreciate your input and comments. Thanks for watching also!
Very helpful sir. Keep on
The "Turn-Around PSI alarm I set on my computer varies depending on depth and/or distance.
For a shallow dive (
That really depends on your dive profile. Theoretically you would use the same amount of gas whether it's a shallow or a deep dive before and after the turnaround, as long as you stay at the same depth, you don't have to swim back against the current, and you're the only one breathing off of your air supply.
Generally speaking, your dive shallows as you return to your point of entry (aiding in off-gassing), and you start your dive going against the current so you can go with the current on the way back. This means you're using less breathing gas on the way back in both scenarios. Splitting it 50/50 already gives you an extra safety margin. In an OOA situation, you end the dive where you are. You don't return to your point of entry underwater in a scenario like that. You do that on the surface.
Love the Superman photo/art on the wall!
Where did you get it???
I'm running out of air nitrox whatever a constant danger it can happen to anybody. Keep a constant watch on your tank pressure gauge.
You should always have an alternate source of breathing gas when you dive.
That can be an extra cylinder and/or a buddy.
And, of course you also need to regularly check your gauges, and do it consciously. Note your air pressure, and compare your next reading to your previous one. Did you use more than you expected? Check for leaks, shallow up, and/or return sooner. If you didn't use any gas, your SPG is broken. End the dive if you don't have a backup.
The reserve pressure is rounded to an easy to remember number. In the US it's 500 psi, in the rest of the world it's 50 bar. It's not exactly the same value after conversion. The same way in the US the first car service is often at 1000 miles, and in the rest of the world it's at 2000 km (instead of 1600 km, which would be the same after conversion).
Also, in the rest of the world, cylinder sizes are measured in physical dimensions, not in maximum capacity. So an Al-80 isn't a 2200 liter, but an 11 liter cylinder. This means it's not immediately obvious when you're comparing cylinders of different sizes and maximum pressures to determine which one will hold the most gas. However, since metric calculations are so much easier to perform than imperial, the maximum capacity can be easily determined by some simple mental arithmetic.
Also, you're almost always dealing with cylinders containing less than maximum fill capacity, and denoting a cylinder as 80 cuft would be considered misleading if there's only 68 cuft of air in there. The physical size of 11 liters is true no matter how much pressurized air it contains.
The rule of thirds is mostly applicable to diving in overhead environments, because you need enough gas to make it out safely if your buddy runs out of air at the deepest point of penetration. For regular open water diving, very few technical divers will apply the rule of thirds.
I recently learned that on penetration dives with DPV's, a rule of fourths is applied when you have a backup DPV, and a rule of sixths if you don't. This is because you cover distance far more quickly with a DPV than you can on your own power. If your DPV fails, you will need to have enough reserve gas to be able to swim back to safety.