Whilst it may be semantics, I look at it as planned or unplanned decompression stop diving.
I suspect it is also a product of a failure to understand that all dives are decompression dives.
One of the issues of PDC's (Personal Dive Computer's) is that the requirement to pre-plan a dive has been removed, i.e. you don't need to look at a set of tables before you get in the water, because the PDC will give you the information on the fly (in real time). With Air Integrated Computers, this requirement is further degraded, because the computer gives you a remaining time based on available gas. This makes people lazy.
This is not how I dive, or teach those I dive with to dive.
For OD (equivalent to PADI OW), it's no stop diving. The rules are 1/3 used at the start of the dive, 1/3 return. On the surface with 1/3 (or 50 bar minimum).
Once you reach Sports Diver, then decompression stop diving is possible. So we always calculate available gas time at the planned depth, and any decompression requirements, and the gas required if we over run depth and/or time.
As a general rule, we always give a maximum planned dive time, i.e the time expected back on the surface (including and stops required).
For square profile dives, (wreck dives, ) this is straight forward. For variable depth dives (like reef dives), it is less ideal - other than you know you planned for the worst case - being deep for the complete length of the dive. It is possible for multi depth dives to plan them as multi depth dives, with the associated gas requirements (after all, that's what a Trimix hard table dive is - multilevel with gas calculations for each depth). But that requires discipline.
In the event that there is an overrun, and either stops are required, or longer than planned stops are required. Divers should have the confidence to follow the recommendation of their computer, and complete all required decompression requirements (Gas permitting).
I dive with a minimum of two computers, and generally, when on CCR or doing adventurous diving, some form of backup hard table.
One issue is some of the newer dive computers appear to have removed the planning function - which is a particular pet peeve of mine!
There are very few reasons to break a decompression stop requirement.
1. To avoid drowning - i.e. if you have run out of gas. (With the associated consequence - but we can generally fix DCI but not drowning).
2. In the event of an Emergency - like when involved in a rescue. (Remember that generally we would prefer rescuers to not put themselves at risk, and add to the complexity of the rescue. But if it was my partner I would probably blow through the stops to get her to the surface and to assistance and take the hit.)
Anyone who blows off stops because the skipper said they are only allowed No Stop dives is an idiot - as is the skipper.
I have seen divers race up the shot because they are near the end of their No-Stop time. This is foolhardy in the extreme.
I have had a good year for diving this year. I have overrun my max time twice this year, both with divers that are new to our group.
1. First time we exited 5 minutes late. I cleared at 55 minutes (on a 60 minute max time dive), my buddy didn't clear for a further 8 minutes. Partly because he was at 6m rather than the 4.5-3m that the computer was basing its calculation on.
Because we where on the shot, I put a DSMB up at 58 minutes, to confirm to the boat our position and that we where OK (a red DSMB).
2. Another new buddy. She didn't realise we where so rigid on our max times (she had more than enough gas). She didn't make the same mistakes on subsequent dives. She extended the stop because she had had a bend a few years earlier. Following dives she added her extension to the TTS shown on the computer. To be honest, it was the longest dives she had done in a few years, with planned run times of 70 minutes.
In both cases there was a lot of sarcasm once we where back on the boat. I have since received a new $5 Casio watch to help me keep to time !
I suspect it is also a product of a failure to understand that all dives are decompression dives.
One of the issues of PDC's (Personal Dive Computer's) is that the requirement to pre-plan a dive has been removed, i.e. you don't need to look at a set of tables before you get in the water, because the PDC will give you the information on the fly (in real time). With Air Integrated Computers, this requirement is further degraded, because the computer gives you a remaining time based on available gas. This makes people lazy.
This is not how I dive, or teach those I dive with to dive.
For OD (equivalent to PADI OW), it's no stop diving. The rules are 1/3 used at the start of the dive, 1/3 return. On the surface with 1/3 (or 50 bar minimum).
Once you reach Sports Diver, then decompression stop diving is possible. So we always calculate available gas time at the planned depth, and any decompression requirements, and the gas required if we over run depth and/or time.
As a general rule, we always give a maximum planned dive time, i.e the time expected back on the surface (including and stops required).
For square profile dives, (wreck dives, ) this is straight forward. For variable depth dives (like reef dives), it is less ideal - other than you know you planned for the worst case - being deep for the complete length of the dive. It is possible for multi depth dives to plan them as multi depth dives, with the associated gas requirements (after all, that's what a Trimix hard table dive is - multilevel with gas calculations for each depth). But that requires discipline.
In the event that there is an overrun, and either stops are required, or longer than planned stops are required. Divers should have the confidence to follow the recommendation of their computer, and complete all required decompression requirements (Gas permitting).
I dive with a minimum of two computers, and generally, when on CCR or doing adventurous diving, some form of backup hard table.
One issue is some of the newer dive computers appear to have removed the planning function - which is a particular pet peeve of mine!
There are very few reasons to break a decompression stop requirement.
1. To avoid drowning - i.e. if you have run out of gas. (With the associated consequence - but we can generally fix DCI but not drowning).
2. In the event of an Emergency - like when involved in a rescue. (Remember that generally we would prefer rescuers to not put themselves at risk, and add to the complexity of the rescue. But if it was my partner I would probably blow through the stops to get her to the surface and to assistance and take the hit.)
Anyone who blows off stops because the skipper said they are only allowed No Stop dives is an idiot - as is the skipper.
I have seen divers race up the shot because they are near the end of their No-Stop time. This is foolhardy in the extreme.
- It puts them at risk, (fast ascents and potential incomplete decompression).
- It puts other divers on the shot at risk.
- It puts all divers in the water at risk. An Incidents means that the crew and other divers are focused on the rescue, not those still in the water.
I have had a good year for diving this year. I have overrun my max time twice this year, both with divers that are new to our group.
1. First time we exited 5 minutes late. I cleared at 55 minutes (on a 60 minute max time dive), my buddy didn't clear for a further 8 minutes. Partly because he was at 6m rather than the 4.5-3m that the computer was basing its calculation on.
Because we where on the shot, I put a DSMB up at 58 minutes, to confirm to the boat our position and that we where OK (a red DSMB).
2. Another new buddy. She didn't realise we where so rigid on our max times (she had more than enough gas). She didn't make the same mistakes on subsequent dives. She extended the stop because she had had a bend a few years earlier. Following dives she added her extension to the TTS shown on the computer. To be honest, it was the longest dives she had done in a few years, with planned run times of 70 minutes.
In both cases there was a lot of sarcasm once we where back on the boat. I have since received a new $5 Casio watch to help me keep to time !
