Nitrox And Air Or Air And Nitrox

what's up guys just running in from Lakers Goodman marina this past week my business partner flew down to Cozumel he took a group of divers with him and while down there there was about a hundred foot wreck that they were on and one of the other divers on the boat made a comment about hey word 100 feet wise nobody using not drops and why there by using air and we've learned in some of our other videos that the higher percentage of nitrox may not necessarily be good for deep diving because of the partial pressures but let's do a little experiment here and see if you are diving a nitrox Ellender and an air cylinder on two different dives or let's say you had night rocks for one dive and air for another dive would it be better to use the night rocks from your deepest dive and then use air on shallow or use air on your deepest dive and use the night rocks bottle for your shell or dive now when I was planning these out I had a little trouble determine what night rocks plan to use but I made it very simple and the way I did it I thought about hey no matter where you go in the world what is the two blends of night rocks you will find regardless and it's 32 percent and 36 percent yes it's a partial pressure blend you can get any blends you want however most places in the tropics don't partial pressure blend they have it banked and you're either only going to get Noah one which is 32 percent or Noah two which is 36 percent and we're going to use 36 percent because it is a richer blend that does have a higher percentage of o2 and for the two depths that I chose of course 70 feet and 40 feet which is a wreck dive and typically reach down something like that that 36 percent is going to work regardless of which one we use it on but let's look real quick and what we're going to base this off of is should I use air first then nitrox or nitrox first then air and we're going to do all our profiles on our men sir force interval because by the way that is one of the neat things about nitrox it shortens our surface interval down so that we can get back in the water a little bit quicker than normal so the only first one I'm going to use the 36% blend first for my deep dive I'm going to see what my minimum surface area is and then I'm going to use air for my 40-foot reef dive now once again I'm going to be using SSI dive tables but you can do the same thing with the paddy table to the Navy table but we're going to just going to be using SSI simply because it's a little bit easier because everything is laid out if you're not familiar with the SSI tables they have the air the NOAA two nitrox thirty-two or NOAA 1 nitrox 32 and NOAA to enrich their nitrox 36 all in the same chart so it's very easy with patties it's really no different you just have three tables that you go to look at or three different sets of dive tables this is kind of everything put together and one so it's a little bit easier so that's one we're going to use SSI so on this first table once again I'm going to be using thirty six percent Night Raw I'm going to 70 feet for forty minutes and it's real simple to do on the tables you simply go to the enriched air 36 column we're going to go down to 70 feet which were of course we would round up and I'm going to scroll over and my bottom column is 40 minutes so I'm scroll over to us he's 40 and that gives me a pressure group of G so I'm go ahead and write that up here and I'm gonna try to do this in color code so it's a little easier to keep up with now to find the minimal surface interval I'll try to do a video on that in the future if you've not familiar with that you should learn it in your open one of course if not I'll link your video on it but I need to find out what my minimum surface interval to do this next dive is and I'm going to be switching over to air because once again we want to know if I should use nitrox on the deep dive and then air on the shallow or air on the deep dive and nitrox on shell so for this next dive is getting on minimum surface interval I've got to kind of reverse the order of the way I work the signals so I'm going to go to Table three I'm going to completely skip the service interval chart and we're straight over my residual engines are which is table 3 and I'm gonna find 40 feet and I will scroll over until I see 60 minutes as my new adjusted time or new Doppler time so simply I go to table 3 I go down on air to 40 feet and then I'm going to scroll over till I see 60 minutes in the bottom number or the next high so 57 be 69 is what it rounds up to and that gives me a pressure group of F so we're go ahead and write that up there and then simply to find the minimum service interval I go back to my table to or surface interval chart and I need to find out how much time it takes to go from a G to an F and that's our minimum surface interval so simply I go to G I'm going to scroll down and then I'm going to scroll over to the intersects with F and it shows me the minimum surface interval here is 41 minutes so to do these two dots safely in that particular order using nitrox 36 first and then air so we'll go to 70 feet for 40 minutes on nitrox 36 then I will go to 40 feet for 60 minutes on plain air the minimum amount of time I have to stay out of the water is 41 minutes now what we're going to do is we're going to do the exact same two dives but we're going to reverse the gas blend or the gas mixture that we're breathing we're going to do the air first and then switch over and do nitrox and see if that shortens our surface interval because that's one of the benefits of nitrox is it shortens your search symbols to get you back in water a little bit quicker so let me redo the board here and I want you to remember 40 once I do up here on the top I'm gonna write 36% and we'll do 41 minutes if we did this one first and then I'll write if we did the air first and see what it comes out there so give me just a second here to clear the chart this changes the air this will change to not drop 36% and will chain just air 74 40 and will change is for you to 60 but will do it on night rocks and will get rid of the thinner part and reduce our calculations again okay so once again we're doing the exact same two dots but we're going to start the dive on air and then we're going to do our next dive on 36 percent and see what our minimal surface interval ends up being after that particular dial so to 110 on this is very simple this time we're going to be using the air column instead of the nitrox 36 we're going to go to 70 feet and we're going to stay for 40 minutes and that puts me in pressure groups H and then we're going to do the exact same thing we're going to go to our shallow dial to 40 feet for 60 minutes but this time we're going to switch over to the nitrox 36 so nitrox 36 I'm going to go to 40 feet now I'm gonna stay for 60 minutes so I have to find 60 in the bottom number of course they would round up to the 73 here that gives me the pressure group of H as well and then all I'm going to do to find the middle and surface integral is intersect H with H which is very simple to do I'll come over here and I find H and H is course here on the bottom so H to H my minimum surface interval would be 10 minutes so in comparison to the first two dots we did use an aurochs first and then air we see it only takes a 10-minute minimum surface interval to do those two dots safely simply by switching the order of the gas we breathe so if we come up here we do air first our minimum service interval is simply ten minutes so anytime that you have two different gas mixtures in general it's going to be better to breed the higher percentage on your second dive than what it is on your first dive now once again we're always going to do our deepest dive first inshallah but if you use that nostril tone you're shallow or dive it will shorten your note decompression limit or I'm sorry your surface interval and it will also extend the note decompression limit as well once again we compared nitrox to air it's always better to do the air die first on your deepest dive then switch over to a nitrox plan or a higher o to blend for your second dial now if you're renting nitrox you're probably going to be diving nitrox on both dogs both first tank and second tank or if you're breathing air you're probably going to be doing both but you never know you may come across a situation where you want to dive nitrox and maybe they've only got one tank to fill or maybe you do want to maximize how much time you get underwater by shorten your service interval and this is a very good easy way to do it on this first one we simply maxed out our no decompression limit so you got the maximum amount of time that you could under the water and of course here we base it off of just your basic bottom time of what the boat captain is going to tell you so that's where we come up with our depth and time or time limitations there but we can clearly see that if you did to 36 percent first on these two profiles it would take 41 minutes before you can get back into water to dive air again but if we did air first it only takes 10 minutes to get back in the water to be if you're diving 36 percent guys will really appreciate you watching this video if you got any questions on these calculations or any questions on the tables whether it's fadi tables or Navy tables or the SSI tables or even PDFs here at the ice table simply put it down the comment section below I'll try to help you out the best I can now if you've got any other questions or comments or concerns or any you want to see a video simply put it down the comment section below we've got a ton of a requests that we're going to try to get out before we get to full fledge into our spring season down summer season and we'll try to get these videos out for you but guys as always makes you pause on Instagram and Twitter like us on Facebook hit that subscribe button here on YouTube pin us on 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Channel: LakeHickoryScuba

Views: 9,606

Rating: 4.9224806 out of 5

Keywords: Lake, Hickory, Scuba, Marina, Taylorsville, North, Carolina, Alexander, County, Diving, Drysuit, Wetsuit, BCD, Regulator, Fins, Mask, Snorkel, Public, Safety, Under, Water, Mares, OS, Systems, Ocean, Reef, Full, Face, Training, XS, Trident, Charter, PDIC, PADI, SEI, CMAS, Educators, International, Search, Recovery, Specialty, Night, Drift, EFR, First, Aid, CPR, AED, Emergency, Oxygen, Provider, Divemaster, Assistant, Instructor, Trainer, Board, Discussion, SSI, School, Commentary, Treasure, Hunting, Noaa, 32%, 36%, 21%, Nitrox, Enriched, Air

Id: g2jVslJZAuY

Length: 11min 25sec (685 seconds)

Published: Sun Feb 26 2017