Free diving depth as part of solo dive certification?

[handben]

I recently decided to take a solo diving course, thinking that "I don't know what I don't know". I figured there might be some new things to learn and I have a couple of trips on the horizon where being able to dive solo will be an asset. So far from the didactic part, I can't say that there is much new information. It is mostly common sense. I have yet to do the in-water practical portion; perhaps there will be more to learn.

One of the requirements of the practical portion is to make a free dive to the deepest I am able to go. My "solo certification" is to twice the depth I am able to go free diving. Maybe I am missing something here, but to me free diving abilities and scuba diving skills are very different. I am having a hard time understanding this as a valid parameter to measure. Have others had this same issue, or is this something specific to my instructor? The book btw says nothing about this as part of the training. Thanks. Ben

 

[Dive-aholic]

What agency is this course through?

 

[LeadTurn_SD]

I recently decided to take a solo diving course, thinking that "I don't know what I don't know". I figured there might be some new things to learn and I have a couple of trips on the horizon where being able to dive solo will be an asset. So far from the didactic part, I can't say that there is much new information. It is mostly common sense. I have yet to do the in-water practical portion; perhaps there will be more to learn.

One of the requirements of the practical portion is to make a free dive to the deepest I am able to go. My "solo certification" is to twice the depth I am able to go free diving. Maybe I am missing something here, but to me free diving abilities and scuba diving skills are very different. I am having a hard time understanding this as a valid parameter to measure. Have others had this same issue, or is this something specific to my instructor? The book btw says nothing about this as part of the training. Thanks. Ben

Hi Ben,

The "idea" behind the "twice your freedive depth" rule is to provide a margin of safety when solo diving.... the idea being that if you can freedive to 40' for example (a total swim of 80' on a single breath), you should be able to self-rescue from 80'.... the reality is that a freedive to 40' is different than a CESA from 80'. Ascent rates are different, risk of embolism, the freedive is performed "clean" (no scuba equipment to add drag)....

I think a better idea is to know what depth you can CESA from, with scuba gear, at a safe rate of ascent (60' minute).

A CESA is a different animal than a freediving ascent..... my ascent rate freediving is probably triple that of a safe scuba ascent rate. And with freediving, the air in my lungs does not need to be vented.....

I think freediving ability is a REALLY good thing to develop.... but don't completely agree with using your max freedive depth as a yardstick for your solo depth.

Using what you consider your max CESA depth might be a way to decide at what depth you should consider a redundant gas supply mandatory. This is what I do, for the environment I dive in (warm, clear, near-nil entanglement risk).

Best wishes.

 

[handben]

@Dive-aholic - SDI.

@LeadTurn - to be frank, I don't know what my CESA max depth is. Given the risks of embolism and DCS, I've not really practiced this skill. I know that it was taught routinely in the early days; but by the time I was open water certified (1983) it had been phased out. I can swim a good distance horizontally on one breath; but I don't think this equates well to CESA. Consequently, I plan to just use a redundant gas supply routinely.

 

[Dive-aholic]

Interesting. The standards say nothing about limiting depth to double the free diving depth... Free diving isn't even part of the standards.

 

[ianr33]

A lot of my solo dives tend to be deep(ish) Maybe 120-150, normally with some deco.

A CESA is simply not an option so I don't even think about it.

 

[dumpsterDiver]

Hi Ben,

The "idea" behind the "twice your freedive depth" rule is to provide a margin of safety when solo diving.... the idea being that if you can freedive to 40' for example (a total swim of 80' on a single breath), you should be able to self-rescue from 80'.... the reality is that a freedive to 40' is different than a CESA from 80'. Ascent rates are different, risk of embolism, the freedive is performed "clean" (no scuba equipment to add drag)....

I think a better idea is to know what depth you can CESA from, with scuba gear, at a safe rate of ascent (60' minute).

A CESA is a different animal than a freediving ascent..... my ascent rate freediving is probably triple that of a safe scuba ascent rate. And with freediving, the air in my lungs does not need to be vented.....

I think freediving ability is a REALLY good thing to develop.... but don't completely agree with using your max freedive depth as a yardstick for your solo depth.

Using what you consider your max CESA depth might be a way to decide at what depth you should consider a redundant gas supply mandatory. This is what I do, for the environment I dive in (warm, clear, near-nil entanglement risk).

Best wishes.

I agree. I can freedive to around 80 feet, but wear a pony at 60 feet for scuba. Developing freediving skills is useful, but trying to equate the two quantiatively makes little sense to me.

In a scuba emergency, you might be working and out of breath. Your ability to work and swim and ascend with no air under these consitions is nothing like a freediver who rests on the surface, slows his heart, prepares mentally and dives in the most gentle and streamlined manner possible. It ain't nothing like trying to ascend in a mild panic with a bunch of scuba gear hanging off you when your heart is pounding in your throat.

Think about it... How long can you hold your breath in the middle of a jog..maybe 20 seconds, while if you hyperventilate a little and practice on the couch, you can probably get two minutes in the living room. There is little comparison.

I never took a solo course, but learning to use redundancy and extricating yourself from entanglements, underwater removal of gear, rock solid gas planning and the ability to evaluate any unique environmental hazards of a particular dive site would seem essential, not limiting your depth to some arbitrary value. I am comfortable solo diving to 200, but freediving ability is not really relevent.

 

[Dyno Bill]

When I was scuba diving a lot I made it a practice to do a esa to stay in touch regularly, I could blow and go from 60 wearing scuba and do a slow controlled ascent without a problem. When I was freediving I would make deeper jumps, not that much deeper as I liked a margin of safety.

 

[knotical]

In Robert von Maier's 1991 book Solo Diving, he calls it rule #1, but also points out that it is just a guideline. His rationale is essentially that staying within this limit increases both the likelihood of being able to successfully do an ESA, and the confidence to do so.

 

[dumpsterDiver]

In Robert von Maier's 1991 book Solo Diving, he calls it rule #1, but also points out that it is just a guideline. His rationale is essentially that staying within this limit increases both the likelihood of being able to successfully do an ESA, and the confidence to do so.

Sorry never read the book or paid attention to the guideline. Maybe I was too busy doing a few thousand solo dives.

Staying shallow will always increase the chance of being able to do a CESA. However, the better you are at freediving, the more stupid this guideline becomes. It is arbitrary, and makes no sense for the reasons I described.

A solo diver should be self sufficient and that means carrying redundant gas supply below a very shallow depth.