iainwilliams
Contributor
Hello,
First, I sent a private message to BRW but I think something went to mush with the message – so if this is a repeat for you I apologise.
There has been a lot of discussion on reverse profiles and see-sawing on the forum – I have read many of the threads and to tell the truth the quantity of information has over whelmed me!
Reverse Profiles: Are reverse profiles safe if conducted after a surface interval greater than 1 hour (say 3 hours) if the depth difference between the shallow and deep dive is no greater than 12 meters?? Should the 3 hours and 12 meters differential be a rule if you are doing reverse profiles?? I’ve read much of the theory and I am now looking for a definitive answer.
See-Sawing: Is see-sawing safe if done below 10 meters?? Is there a depth differential in relation to the depth change that is safe??
An example maybe a dive to 38 meters maximum, followed by a rise in depth to 28 meters (to say follow a fish), then a decent back to 38 meters. Is this safe? (assuming NDL’s are OK) and assuming a few minutes were spent at the shallower dpeth before decending again.
Personally, I am rather anal when it comes to depth rules. I always do the deepest dive first, always have a longer than 1 hour surface interval, and always NEVER go deeper than the maximum depth attained initially during a dive. I also use pyle stops (half the maximum depth first stop for 2 minutes and so on) and do two safety stops (usually) - one at 5m the other at 3m. However, lately I have been doing quite a bit of diving in PNG and I notice that many divers do not share my philosophy. They do reverse profiles, chase fish up and down the water column with depth changes of 10 meters plus – and they never get bent! Perhaps I am being far too conservative in my approach to dive safety.
I look forward to, hopefully, some straight forward and easy to use guidelines. Thank you………..Iain
First, I sent a private message to BRW but I think something went to mush with the message – so if this is a repeat for you I apologise.
There has been a lot of discussion on reverse profiles and see-sawing on the forum – I have read many of the threads and to tell the truth the quantity of information has over whelmed me!
Reverse Profiles: Are reverse profiles safe if conducted after a surface interval greater than 1 hour (say 3 hours) if the depth difference between the shallow and deep dive is no greater than 12 meters?? Should the 3 hours and 12 meters differential be a rule if you are doing reverse profiles?? I’ve read much of the theory and I am now looking for a definitive answer.
See-Sawing: Is see-sawing safe if done below 10 meters?? Is there a depth differential in relation to the depth change that is safe??
An example maybe a dive to 38 meters maximum, followed by a rise in depth to 28 meters (to say follow a fish), then a decent back to 38 meters. Is this safe? (assuming NDL’s are OK) and assuming a few minutes were spent at the shallower dpeth before decending again.
Personally, I am rather anal when it comes to depth rules. I always do the deepest dive first, always have a longer than 1 hour surface interval, and always NEVER go deeper than the maximum depth attained initially during a dive. I also use pyle stops (half the maximum depth first stop for 2 minutes and so on) and do two safety stops (usually) - one at 5m the other at 3m. However, lately I have been doing quite a bit of diving in PNG and I notice that many divers do not share my philosophy. They do reverse profiles, chase fish up and down the water column with depth changes of 10 meters plus – and they never get bent! Perhaps I am being far too conservative in my approach to dive safety.
I look forward to, hopefully, some straight forward and easy to use guidelines. Thank you………..Iain
