help with a PADI altitude diver?

[ASert]

quick review ? is you wish to dive 24m/80ft after arriving at 1382m/4532ft after you have been there for one hour what is your NDL? and what is it after six hrs.

ok so 1382m puts me at J group with one hour surface interval puts me at pg C so you dive to 24m/80 i see a NDL of 20min with a RNT of 10

the book answer says it is 12 and 20 if it is 12 where am i calculating wrong?

 

[Agility]

are you using altitude tables or tables for sea level?

 

[ASert]

idk its a question in the adventures in diving book for altitude diving?

 

[genxweb]

Did you use the theoretical Depth at altitude chart? The 20 is correct if you do the standard if you do the theoretical depth you need to round your depth up which would give you at 5000' altitude 96' foot dive. So C down to 100' as you have to round up gives you 12.



That is not the official PADI chart there is an official one in your book. This one is for reference.

Remember after 6 hours of arriving at altitude PADI says your residual nitrogen is gone and your dive counts as the first dive of the day.

 

[ASert]

thank you

 

[genxweb]

Not a problem . Glad I could help.

 

[Halfcan]

I am also having trouble with this same section. I understand how Asert got confused with using the theoretical chart or the RDP, the book does not distinguish which table to use.

Here the the two questions that are giving me trouble:

You plan to dive to an actual depth of 18meters/60 ft one hour after you arrive at an altitude of 1090 meters/3578. If you were to dive to the no decompression limit, what would your no decompression limit be for a repetitive dive to the same depth after a 45 min surface interval?

Using the RDP, I account for 3578 ft being 4000 and count two pressure groups for each 1000 ft. This gets me to H and I go over to 1h SI and that puts me in group B.. I flip the chart and take B down to 60 ft which gives me a 44 no decompression limit. This is where I get lost... what do I need to do next to figure out the answer to the last part of the question(If you were to dive to the no decompression limit, what would your no decompression limit be for a repetitive dive to the same depth after a 45 min surface interval?)


Any help would be greatly appreciated. Thanks.

 

[Scott]

You plan to dive to an actual depth of 18meters/60 ft one hour after you arrive at an altitude of 1090 meters/3578. If you were to dive to the no decompression limit, what would your no decompression limit be for a repetitive dive to the same depth after a 45 min surface interval?

Using the RDP, I account for 3578 ft being 4000 and count two pressure groups for each 1000 ft. This gets me to H and I go over to 1h SI and that puts me in group B.. I flip the chart and take B down to 60 ft which gives me a 44 no decompression limit. This is where I get lost... what do I need to do next to figure out the answer to the last part of the question(If you were to dive to the no decompression limit, what would your no decompression limit be for a repetitive dive to the same depth after a 45 min surface interval?)

Take your depth of 60 feet and convert it to theoretical, which would be 69 feet. Then it becomes a "typical" dive profile. Your NDL is no longer :44.

 

[Halfcan]

Take your depth of 60 feet and convert it to theoretical, which would be 69 feet. Then it becomes a "typical" dive profile. Your NDL is no longer :44.

Scott,

So is my new NDL 31?? What about figuring out the next part? (If you were to dive to the no decompression limit, what would your no decompression limit be for a repetitive dive to the same depth after a 45 min surface interval?)

Thanks. I guess you are the person to ask about altitude diving since you are in SLC.