1389 replies to this topic

[AliKat]

I think Pittsburg is inland enough. Shouldn't be too affected. And you're on the later flight out of Houston, so even if your flights delayed a little you should be fine.

[OHDiver]

I think Pittsburg is inland enough. Shouldn't be too affected. And you're on the later flight out of Houston, so even if your flights delayed a little you should be fine.

That's exactly what I'm hoping...
We are getting tons of rain here in OH already, bad enough I have to drive in it most of the day tomorrow...

[Jellyfishluv]

…Yeah guys, don’t worry about memorizing formulas, that’s not what “they” should want, i.e. PADI, SSI, or NAUI – they should just want you to know how to use the formulas – they should be provided with the exam.

Dive computers! Yes, remembering to set the O2 amount after you’ve checked and marked your tanks is the most important task, and if you are diving both Nitrox & Air on the same day, you may run into the problem I did: After two dives on Nitrox I tried to switch my Sherwood Wisdom computer back to air – no luck. The no brainer here everyone? Just set your O2 to 21% !!!!!!

Now for the fun stuff: NOAA has an “Oxygen Exposure Limits” Table for those diving multiple dives/days on Nitrox. If for example, your PO2 (ATA) for dive #1 equals 1.4, your maximum Single Dive Exposure Limit (in minutes) is 150 and your Max. Total Exposure Duration for any 24 hr period (in Minutes) will be 180 = 3 hours of diving: if you dive 60 min dives that = 3 dives per day max.

How do you reach a 1.4 PO2 (ATA) per dive: use the Oxygen “T” formula: We’ll assume all dives have to be 36% Nitrox

1.45
___________
36% ] 4.03

36% Is the fraction of oxygen in the mixture (FO2)
4.03 is total pressure ATA at the max depth (PT): (I assumed 100ft)= (Depth/33) +1 ATA
(PO2) is the product of the bottom two numbers: (FO2xPT)= (.36x4.03=1.45)
So if you dive Nitrox 36% to 100ft you have set your Oxygen Exposure limits to 150 for a single dive (great air consumption if you stay down that long!) but more importantly, you have limited yourself to at total of 180 minutes for the day! (safety measure: we would actually have to round 1.45 up to 1.5 changing our Max Single Dive Exposure to 120 and 180 for 24 hrs, the same Total per day as 1.45 so I used that)

NOAA also has the “Repex Oxygen Exposure” Table & the “Maximum Oxygen Exposure Limits for Pulmonary Oxygen Toxicity” Table If we use the above dive example and extend it to the following two tables the first step is to calculate our PO2 in ATM on the “Repex” Table because that is what is used is used (not PO2 in ATA as above), so in the Oxygen “T” formula, 4.03 (PT) is recalculated as follows:
Depth/33=ATM or 100/33=3.03 ATM
Multiply that with the mixture 36% and our PO2 in ATM= 1.09

Next the table pairs up PO2(ATM) with the term oxygen tolerance units (OTU’s). On the “Repex” Table OTU’s are shown per minute. Since the above example gives us a PO2 of 1.09 it is rounded up to 1.10 and our OTU per minute is rounded 1.16.

This OTU is multiplied by the number of minutes per dive so say 60min dive= 1.16x60=69.6 OTU’s per dive.

On the “Max. Oxygen Exposure Limits for Pulmonary Oxygen Toxicity” Table we are given: Period (days), Max Daily Dose (OTU) and Total Expose (OTU) for that period.

For six days of diving the Max Daily dose (OTU) is 350= and Total Exposure for 6 days is 2520

Since our (OTU) per 60 minute dive is 69.6 in this example we would calculate how many dives we can do in a day: (350/69.6= 5, 60min dives) and for the six day period (2520/69.06=36, 60 min dives)
I’ve laid out an example in the maximum Nitrox mix we can use as Nitrox divers (36%) and the maximum depth recommended while diving on Nitrox to find out the maximum number of dives we could dive if, this was the scenario.

It is safe to say that we could, if we wanted to, dive 6 or even 7 dives a day if the depth and mix changed. I will not recalculate – I will just use this example as a guide.

THANK GOODNESS FOR DIVE COMPUTERS!!!!

Edited by Jellyfishluv, 31 August 2006 - 09:54 PM.

[AliKat]

…
THANK GOODNESS FOR DIVE COMPUTERS!!!!

That last sentence says it all!

[Stingray1]

Alrighty then .....
I will be arriving in Houston at 6:30 am and I'll find a restaurant close to the departing gate for the 10:30 flight to Roatan. If you'd like to join me, call my cell phone and I'll tell you where I am
I am soooo looking forward to this vacation

We'll probably be flying out of Terminal E. They have a food court on the gate level (you'll probably pass it on the way to the gate) and also a Pappadeaux upstairs above the gates.
I'm not bringing a phone, but I wrote down your #. If we don't run in to you, we'll call.

[OHDiver]

…Yeah guys, don’t worry about memorizing formulas, that’s not what “they” should want, i.e. PADI, SSI, or NAUI – they should just want you to know how to use the formulas – they should be provided with the exam.

Dive computers! Yes, remembering to set the O2 amount after you’ve checked and marked your tanks is the most important task, and if you are diving both Nitrox & Air on the same day, you may run into the problem I did: After two dives on Nitrox I tried to switch my Sherwood Wisdom computer back to air – no luck. The no brainer here everyone? Just set your O2 to 21% !!!!!!

Now for the fun stuff: NOAA has an “Oxygen Exposure Limits” Table for those diving multiple dives/days on Nitrox. If for example, your PO2 (ATA) for dive #1 equals 1.4, your maximum Single Dive Exposure Limit (in minutes) is 150 and your Max. Total Exposure Duration for any 24 hr period (in Minutes) will be 180 = 3 hours of diving: if you dive 60 min dives that = 3 dives per day max.

How do you reach a 1.4 PO2 (ATA) per dive: use the Oxygen “T” formula: We’ll assume all dives have to be 36% Nitrox

1.45
___________
36% ] 4.03

36% Is the fraction of oxygen in the mixture (FO2)
4.03 is total pressure ATA at the max depth (PT): (I assumed 100ft)= (Depth/33) +1 ATA
(PO2) is the product of the bottom two numbers: (FO2xPT)= (.36x4.03=1.45)
So if you dive Nitrox 36% to 100ft you have set your Oxygen Exposure limits to 150 for a single dive (great air consumption if you stay down that long!) but more importantly, you have limited yourself to at total of 180 minutes for the day! (safety measure: we would actually have to round 1.45 up to 1.5 changing our Max Single Dive Exposure to 120 and 180 for 24 hrs, the same Total per day as 1.45 so I used that)

NOAA also has the “Repex Oxygen Exposure” Table & the “Maximum Oxygen Exposure Limits for Pulmonary Oxygen Toxicity” Table If we use the above dive example and extend it to the following two tables the first step is to calculate our PO2 in ATM on the “Repex” Table because that is what is used is used (not PO2 in ATA as above), so in the Oxygen “T” formula, 4.03 (PT) is recalculated as follows:
Depth/33=ATM or 100/33=3.03 ATM
Multiply that with the mixture 36% and our PO2 in ATM= 1.09

Next the table pairs up PO2(ATM) with the term oxygen tolerance units (OTU’s). On the “Repex” Table OTU’s are shown per minute. Since the above example gives us a PO2 of 1.09 it is rounded up to 1.10 and our OTU per minute is rounded 1.16.

This OTU is multiplied by the number of minutes per dive so say 60min dive= 1.16x60=69.6 OTU’s per dive.

On the “Max. Oxygen Exposure Limits for Pulmonary Oxygen Toxicity” Table we are given: Period (days), Max Daily Dose (OTU) and Total Expose (OTU) for that period.

For six days of diving the Max Daily dose (OTU) is 350= and Total Exposure for 6 days is 2520

Since our (OTU) per 60 minute dive is 69.6 in this example we would calculate how many dives we can do in a day: (350/69.6= 5, 60min dives) and for the six day period (2520/69.06=36, 60 min dives)
I’ve laid out an example in the maximum Nitrox mix we can use as Nitrox divers (36%) and the maximum depth recommended while diving on Nitrox to find out the maximum number of dives we could dive if, this was the scenario.

It is safe to say that we could, if we wanted to, dive 6 or even 7 dives a day if the depth and mix changed. I will not recalculate – I will just use this example as a guide.

THANK GOODNESS FOR DIVE COMPUTERS!!!!

WOW!
Now you're really scaring me...

[OHDiver]

OK... who can tell me what I do once I arrive in Roatan???
I'm thinking I better figure this out this morning some time, as I will be heading out on my road trip part of this in a few hours... I'm not sure if I will have access to a computer and the SD site once I'm outta here...
Do I simply look for a Fantasy Island shuttle or will someone be holding a sign of some sort??? Someone??? Anyone???
As far as I know, there will only be three of us coming in on that later flight...

Can't wait to meet everyone...

Karen

[Latitude Adjustment]

OK... who can tell me what I do once I arrive in Roatan???
I'm thinking I better figure this out this morning some time, as I will be heading out on my road trip part of this in a few hours... I'm not sure if I will have access to a computer and the SD site once I'm outta here...
Do I simply look for a Fantasy Island shuttle or will someone be holding a sign of some sort??? Someone??? Anyone???
As far as I know, there will only be three of us coming in on that later flight...

Can't wait to meet everyone...

Karen

Fantasy Island will be there with a bus for you and a truck for your baggage.

[ASDmike]

...what I do once I arrive in Roatan???

follow Ray

my spies tell me a certain wenchie may be on my plane, so I know who I'll be stalki... trailing

Well, in IAH I guess that works until she passes the presidents club... then I have to choose

[scubaguyd]

Simple. Again, ifn you have to set your computer dont forget to set it after you analyze and mark you tank.

And, if it is a nasty beastie like mine, the default is it will go to 50% if you don't update it between dives - so this is a task added to every dive's checklist.

ps - for scubaguyd, I got a recall notice from the USN - check your scubaguyd.com address - you may have one too....

Reporting in for recall notice AyeAye capn. will arrive 1330 , ARRR me capn at ye service standing TALL with me long blade! ready to use me sabarrr at a moment notice. Me will serve harrrrrd semperfi me capn.

Edited by scubaguyd, 01 September 2006 - 07:56 AM.

[VAglassman]

…Yeah guys, don’t worry about memorizing formulas, that’s not what “they” should want, i.e. PADI, SSI, or NAUI – they should just want you to know how to use the formulas – they should be provided with the exam.

Dive computers! Yes, remembering to set the O2 amount after you’ve checked and marked your tanks is the most important task, and if you are diving both Nitrox & Air on the same day, you may run into the problem I did: After two dives on Nitrox I tried to switch my Sherwood Wisdom computer back to air – no luck. The no brainer here everyone? Just set your O2 to 21% !!!!!!

Now for the fun stuff: NOAA has an “Oxygen Exposure Limits” Table for those diving multiple dives/days on Nitrox. If for example, your PO2 (ATA) for dive #1 equals 1.4, your maximum Single Dive Exposure Limit (in minutes) is 150 and your Max. Total Exposure Duration for any 24 hr period (in Minutes) will be 180 = 3 hours of diving: if you dive 60 min dives that = 3 dives per day max.

How do you reach a 1.4 PO2 (ATA) per dive: use the Oxygen “T” formula: We’ll assume all dives have to be 36% Nitrox

1.45
___________
36% ] 4.03

36% Is the fraction of oxygen in the mixture (FO2)
4.03 is total pressure ATA at the max depth (PT): (I assumed 100ft)= (Depth/33) +1 ATA
(PO2) is the product of the bottom two numbers: (FO2xPT)= (.36x4.03=1.45)
So if you dive Nitrox 36% to 100ft you have set your Oxygen Exposure limits to 150 for a single dive (great air consumption if you stay down that long!) but more importantly, you have limited yourself to at total of 180 minutes for the day! (safety measure: we would actually have to round 1.45 up to 1.5 changing our Max Single Dive Exposure to 120 and 180 for 24 hrs, the same Total per day as 1.45 so I used that)

NOAA also has the “Repex Oxygen Exposure” Table & the “Maximum Oxygen Exposure Limits for Pulmonary Oxygen Toxicity” Table If we use the above dive example and extend it to the following two tables the first step is to calculate our PO2 in ATM on the “Repex” Table because that is what is used is used (not PO2 in ATA as above), so in the Oxygen “T” formula, 4.03 (PT) is recalculated as follows:
Depth/33=ATM or 100/33=3.03 ATM
Multiply that with the mixture 36% and our PO2 in ATM= 1.09

Next the table pairs up PO2(ATM) with the term oxygen tolerance units (OTU’s). On the “Repex” Table OTU’s are shown per minute. Since the above example gives us a PO2 of 1.09 it is rounded up to 1.10 and our OTU per minute is rounded 1.16.

This OTU is multiplied by the number of minutes per dive so say 60min dive= 1.16x60=69.6 OTU’s per dive.

On the “Max. Oxygen Exposure Limits for Pulmonary Oxygen Toxicity” Table we are given: Period (days), Max Daily Dose (OTU) and Total Expose (OTU) for that period.

For six days of diving the Max Daily dose (OTU) is 350= and Total Exposure for 6 days is 2520

Since our (OTU) per 60 minute dive is 69.6 in this example we would calculate how many dives we can do in a day: (350/69.6= 5, 60min dives) and for the six day period (2520/69.06=36, 60 min dives)
I’ve laid out an example in the maximum Nitrox mix we can use as Nitrox divers (36%) and the maximum depth recommended while diving on Nitrox to find out the maximum number of dives we could dive if, this was the scenario.

It is safe to say that we could, if we wanted to, dive 6 or even 7 dives a day if the depth and mix changed. I will not recalculate – I will just use this example as a guide.

THANK GOODNESS FOR DIVE COMPUTERS!!!!

Oh...... my headache just got so much worse, just reading this post!!

[Stingray1]

If anyone is flying out of Houston on the early Continental flight # 1894, this is one of the international flight you can check in online and get your boarding pass. You will need your passport # and expiration date.
I've checked in and have my boarding pass.
See ya'll in the morning!

[AliKat]

If anyone is flying out of Houston on the early Continental flight # 1894, this is one of the international flight you can check in online and get your boarding pass. You will need your passport # and expiration date.
I've checked in and have my boarding pass.
See ya'll in the morning!

Thanks. I'll do that right now.

[AliKat]

I am also on CO 1894 on 09/02.

See everyone there

Ditto

PlatypusMan
...Roatan! Roatan!! Roatan!!!

I'm also on that flight seat 20F

I think I'm in 21F - I'll be sure and kick the back of the seat the whole flight

You won't have too far to reach it'll be reclined in your lap the whole way.

Actually, I got the flights mixed up - I'm in 21a from HNL - I'm in 19F from Houston. So, I guess I get to recline in YOUR lap and you can kick the back of the seat

[OHDiver]

WAAHOO!!!

I'm outta here and starting the road trip part of my Roatan journey...

See you all there tomorrow....

Karen