Deep Diving Specialty

[reggiehg]

Hi,

I'm supposed to have gotten my deep diving specialty last December, but I'm wondering if I really learned anything :11:. All I remember is we went to 40 meters and then slowly made our ascent. Is that really all there is to it? Or should I have learned anything more?

I'm confused because according to the RDP, I have 9 minutes max if I dive to 40 meters. But what we actually did was stay about 2 minutes at 40 meters, and then ascended relatively slow, so that our total bottom time was much, much more than 9 minutes.

I'm sure the dive was safe, and my question pertains more to the technique of planning such a dive. My instructor says that the technique we did pertains more to multi-level diving than to deep diving. Is that true?

If it is, then I don't think I really learned anything new from my deep diving speciality since I learned to use the RDP, which is good to 42 meters, from my OW license. Plus, all I can take responsibility for by myself when deep diving to 40 meters is a bottom time of 9 minutes, which seems ridiculous.

Or am I missing something?

Regards,

Reggie

 

[Whitelightnin]

There are a couple of things that you are suppposed to learn in the deep diving specialty. One is how color is affected by depth. The instructor usually has some colored items that you look at at depth with & without additional light. Another is how pressure affects objects at depth. Usually this involves a soda bottle or tennis ball. You get to see what happens to them at depth.

Probally the most important things you learn are how fast you use air at that depth & what it's like to be affected by narcosis. It is a very good idea to have someone experienced with you when you do your first deep dive. You don't know how narcosis will affect you & it's possible you might not get a second chance.

James

 

[ppo2_diver]

Sounds like you got the standard "book" type course. You really should have learned more about gas management and making sure your basic skills (i.e. buoyancy, trim, air sharing, no mask, etc.) are up to snuff. You should have also learned about narcosis and carbon dioxide build up.

The profile sounds safe enough. This sounds like your basic, by the book, recreational deep class. Which, IMHO, is not sufficient for dives deeper than 60 feet. Deeper diving carries increased risk, even for recreational deep limits.

 

[shurite7]

Personally I think the deep diving specialty is a frivolous certification, but that is my opinion.

However, there are some things you should have learned in the course;

air consumption...Did you noticed your air supply was being depleted much faster than normal? That may have been the reason why you didn't stay at 40 meters over 2 minutes.

Multi-level diving....pretty much all recreational deep dives encompass multi-level. At least those with most dive resorts. Not everyone in the group consumes air at the same rate so the guide may bring the group to a shallower depth to keep the group from splitting apart due to lack of air.

Narcosis....Did you do any type of skill/function or game while at depth? This would give you a chance to encure narcosis while diving with an experienced person.

Salaam

Chris

 

[KMD]

Hi,

I'm supposed to have gotten my deep diving specialty last December, but I'm wondering if I really learned anything :11:. All I remember is we went to 40 meters and then slowly made our ascent. Is that really all there is to it? Or should I have learned anything more?

Absolutely you should have learned more. You should be able to answer the following questions before you even get into the water on a dive such as this:

Gas planning:
What is the minimum gas I need to reserve on such a dive?
What is my expected bottom time and how does that relate to NDL?
What is my sac rate?
What is my gas comsumption at depth?
What type of ascent strategy will you be using?
What is your emergency ascent strategy?
What is your dive plan? Out and back? Drift dive? 3rds?
What is your total gas comsumption for the dive?
What effect does the answers of these questions have on my cylinder choice?

Awareness:
What type of communication do I need to utilize within my team?
What effect does narcosis have on me? Should I be looking to add other gas mixes?
How do conditions topside and underwater affect such a dive?

Training:
What type of training should me and my team have when attempting such a dive?
Do I have sufecient level of experience? Can I hold stops? Can I perform required tasks at depth when needed.
Have I suficiently trained in emergency procedures?

Gear choice:
For such a dive what type of equipment is Sub-optimal? Acceptable? Preferred? Required?

Risk Analysis:
What are the risks of such a dive?
What are the avoidable risks?
What are the inherent risks?
Have I eliminated the avoidable risks?
Have I mitigated the inherant risks?
What is my risk tollerance?
What is the risk tollerance of my team?
Is the dive worth the risk?

 

[Captain Hardhead]

My instructer took us 3 feet below our planned dive (100 fsw) and made me pull out my rdp and re-figure our bottom time/plan.

He also made me rig a tank with a reg to hang at 15 ft. below the boat before the dive in case we had a low air issue.

 

[Rick Inman]

I'm with KMD on this.

I'm confused because according to the RDP, I have 9 minutes max if I dive to 40 meters. But what we actually did was stay about 2 minutes at 40 meters, and then ascended relatively slow, so that our total bottom time was much, much more than 9 minutes.

If you went right down to 40 meters and stayed only 2 mins before doing a slow ascent, what do you think your "bottom time" was?

 

[Karibelle]

Hi,

I'm supposed to have gotten my deep diving specialty last December, but I'm wondering if I really learned anything :11:. All I remember is we went to 40 meters and then slowly made our ascent. Is that really all there is to it? Or should I have learned anything more?

What agency was the course through? Did you do just one dive?

kari

 

[mjatkins]

It sounds as if what you did was a less than usefull deep "adventure dive". If you had done a PADI deep diver specialty, it should involve reading the deep diver manual, watching the video, working through the knowledge development with your instructor, and then doing 4 open water deep dives. Each of these dives has skills associated with it that you would need to complete. When you have completed this you would receive the deep diver certification which has a certification card.

Are you sure you didn't do this dive as part of your advanced open water course, which would only be one deep dive, plus four other "adventure" dives.

Matthew

 

[Steve50]

Absolutely you should have learned more. You should be able to answer the following questions before you even get into the water on a dive such as this:

Gas planning:
What is the minimum gas I need to reserve on such a dive?
What is my expected bottom time and how does that relate to NDL?
What is my sac rate?
What is my gas comsumption at depth?
What type of ascent strategy will you be using?
What is your emergency ascent strategy?
What is your dive plan? Out and back? Drift dive? 3rds?
What is your total gas comsumption for the dive?
What effect does the answers of these questions have on my cylinder choice?

Awareness:
What type of communication do I need to utilize within my team?
What effect does narcosis have on me? Should I be looking to add other gas mixes?
How do conditions topside and underwater affect such a dive?

Training:
What type of training should me and my team have when attempting such a dive?
Do I have sufecient level of experience? Can I hold stops? Can I perform required tasks at depth when needed.
Have I suficiently trained in emergency procedures?

Gear choice:
For such a dive what type of equipment is Sub-optimal? Acceptable? Preferred? Required?

Risk Analysis:
What are the risks of such a dive?
What are the avoidable risks?
What are the inherent risks?
Have I eliminated the avoidable risks?
Have I mitigated the inherant risks?
What is my risk tollerance?
What is the risk tollerance of my team?
Is the dive worth the risk?

Sorry for the long quote but - that was nice KMD!