Diving to 42 metres for emergency purposes

[supercritical]

The PADI RDP says not to dive to 42 metres except for emergency purposes. I'm curious: what are these 'emergency purposes'?

 

[tamas970]

When you want to save your buddy's life (e.g. he/she has difficulties/got narced and sunk deeper than planned). It's quite a tough decision to turn back, if you are at the limit. If I saw a buddy/family member sinking to 45m, I certainly wouldn't stop and let her/him die 3meters away...

 

[DevonDiver]

Very few 'emergency purposes' really. Maybe to complete a rescue of another sinking diver?

Having that information allows you to plan subsequent dives in the event that you accidentally exceeded your 40m limit for a (very) short period on the preceeding dive. If they didn't have it on the table and stated only 'don't dive again that day', people would probably ignore the exceeded depth and continue planning as per 40m dive - thus exposing them to more risk of DCI due to improperly calculated surface interval/repetitive dive...

 

[tamas970]

That's one more reason to dive with a capable dive computer. Although one might not have the appropriate training for performing deco stops, he/she can reduce the trouble quite a lot. (however, I don't know how efficient an all-air deco can be...)

Very few 'emergency purposes' really. Maybe to complete a rescue of another sinking diver?

Having that information allows you to plan subsequent dives in the event that you accidentally exceeded your 40m limit for a (very) short period on the preceeding dive. If they didn't have it on the table and stated only 'don't dive again that day', people would probably ignore the exceeded depth and continue planning as per 40m dive - thus exposing them to more risk of DCI due to improperly calculated surface interval/repetitive dive...

 

[Abdullah]

That's one more reason to dive with a capable dive computer. Although one might not have the appropriate training for performing deco stops, he/she can reduce the trouble quite a lot. (however, I don't know how efficient an all-air deco can be...)

Nitrox and Oxygen accelerate the deco schedule, making for shorter hang times on planned dives, but aren't required for deco. You just need enough air in your tank to complete the deco obligation, and some way to know what that obligation is.

 

[supercritical]

I understand now. Thanks.