Planned deco on a recreational dive?

[EricTheDood]

The line between no stop and deco diving is very clear.

With no stop diving, follow your computer and monitor your air. Gas planning is an afterthought.

With deco diving, gas planning is necessary.

It's not about danger, it's about planning.

 

[Diver-Drex]

It's not a tec vs rec question. And it's not a matter of what an organization teaches at what level. It's a matter of properly planning dives and following that plan. Assess risks and plan to mitigate those risks to acceptable levels.
Is incurring a 10 minute deco obligation in good conditions more or less risk than a normal NJ wreck dive? Doesn't it depend on whether or not you have the training, experience and equipment to handle the dive?
Maybe blowing off a few minutes of deco because you don't have enough gas to complete your stops isn't a big deal. Maybe your computer is too conservative. Maybe if you had changed a setting on your computer it wouldn't even have gone into a deco obligation. But it's far too easy to plan a dive, have the right equipment and carry redundant gas to ever have to find out.

 

[Diver-Drex]

The line between no stop and deco diving is very clear.

With no stop diving, follow your computer and monitor your air. Gas planning is an afterthought.

With deco diving, gas planning is necessary.

It's not about danger, it's about planning.

Gas planning is not an after thought, ever. Ensuring you have something to breath is the first thought. This is a tremendous failure of the training organizations to not make this point and to not teach basic gas planning skills.

 

[oldschoolto]

Planning gas is "ONLY for TEC" ... WOW, I guess I can do any dive on a LP 40 or maybe a 63cu or how about a 6cu spare air....

Jim...

 

[EricTheDood]

Gas planning is not an after thought, ever. Ensuring you have something to breath is the first thought. This is a tremendous failure of the training organizations to not make this point and to not teach basic gas planning skills.

Planning gas is "ONLY for TEC" ... WOW, I guess I can do any dive on a LP 40 or maybe a 63cu or how about a 6cu spare air....

Jim...

Using general guidelines, like rule of thirds, or heading up to do a 3 minute safety stop at 800psi, hardly qualifies as gas planning. Choosing a bigger tank to extend your bottom time by some unknown amount also doesn't qualify as gas planning.

To me, gas planning at the minimum involves calculations with you and your buddy's SAC rates.

 

[Diver-Drex]

Indeed, heading up for a safety stop when you reach 800psi isn't gas planning.
The fact that you believe that only tec divers should discuss SAC is an issue.
The fact that you believe you only need to discuss gas consumption prior to a deco stop dive is an issue.
At 60fsw most new divers using an AL80 will run out of gas before running out of NDL time. Your told how to use a table or how to use your brand new $500 computer, but not how to determine that your real limit is gas consumption. That is a problem.

 

[EricTheDood]

Indeed, heading up for a safety stop when you reach 800psi isn't gas planning.
The fact that you believe that only tec divers should discuss SAC is an issue.
The fact that you believe you only need to discuss gas consumption prior to a deco stop dive is an issue.
At 60fsw most new divers using an AL80 will run out of gas before running out of NDL time. Your told how to use a table or how to use your brand new $500 computer, but not how to determine that your real limit is gas consumption. That is a problem.

Going into deco means there's a virtual overhead environment, which is the reason why gas planning is so important. You can also be in a real overhead environment without going into deco, and that also requires gas planning.

You say it's a problem that most new divers don't know how to calculate their gas consumption. I'd say it's safer for them to blindly follow typical guidelines, which are generally conservative, than to attempt to calculate gas consumption, for which they're not qualified to do anyway. Gas planning is NOT a good thing if done incorrectly.

 

[KenGordon]

The line between no stop and deco diving is very clear.

With no stop diving, follow your computer and monitor your air. Gas planning is an afterthought.

With deco diving, gas planning is necessary.

It's not about danger, it's about planning.

There are many sorts of dives that require proper gas planning. It is an essential skill. If you can't do that then you deserve to be nannied by DMs.

Any dive with a return to shot, any half seriously deep dive, any dive with a rough surface. These can easily be within NDL but having no gas and the surface not immediately reachable or bad consequences of hitting the surface in the wrong place mean that diving without a gas plan is reckless.

Ok, so I just thought, maybe these people think gas planning is magic because they have not learned it. So, never having done a PADI course I went to try to figure out if it was taught. I find mention of it in the Tec 40 course so I assume that it is not in AOW. That seems like a mistake to me.

Personally, I don't think people should be let out of the house unaccompanied if they can't do gas planning.

 

[Patoux01]

Ok, so I just thought, maybe these people think gas planning is magic because they have not learned it. So, never having done a PADI course I went to try to figure out if it was taught. I find mention of it in the Tec 40 course so I assume that it is not in AOW. That seems like a mistake to me.

Personally, I don't think people should be let out of the house unaccompanied if they can't do gas planning.

I'll go through my OW book this week-end, I learned most of my diving outside of courses (forums are wonderful ), so I don't remember exactly what was in the book and what I found elsewhere at the time. Since OW divers should be able to plan their dive, I expect there is some level of gas management in it, even very light.

Agreed with the 2nd statement. (But I'd add they also need to be taught "scuba common sense").

You say it's a problem that most new divers don't know how to calculate their gas consumption. I'd say it's safer for them to blindly follow typical guidelines, which are generally conservative, than to attempt to calculate gas consumption, for which they're not qualified to do anyway. Gas planning is NOT a good thing if done incorrectly.

So we can then nicely go after the guys that actually researched their stuff and decided to not follow the guidelines. Sounds like a plan. (not targeted at you, but at some other posters here)

 

[Freewillow]

I almost always dive with my wife. It is always in good viz and nice temperature and no overhead environment. We NEVER loose sight of one another and we have comparable consumption rates, taking into account the fact that she carries a 12L and I carry a 15L.

Most of our dives are "planned" in the sense that we know at what pressure we need to go up. It is a very easy formula derived from your TTS ( time to surface - including deco stop ).