Sport Chalet Instruction...new rules

[SparticleBrane]

i just got my computer a couple weeks ago and have not read the manual for it.

i do think most people are too [-]stupid/busy/arrogent/etc[/-] lazy to spend an hour at the most reading the manual to understand their own piece of equipment.

There, I fixed it for you.

You've have the computer for "a couple weeks" and you haven't spent a few minutes to read the manual? Instead of piddling around on scubaboard, go read the manual for your computer.
Your own post proved your point.

 

[The Chairman]

Can you explain how you teach students how to use computers and not be reliant on them in the event of a failure?

Why would I want to? As Ann Marie pointed out, when EVER you have a primary equipment failure, you simply end the dive.

I have to admit that I also teach reliance on a student's Regulator, BC, mask, fins and should any of these items fail, I also recommend terminating the dive. I'm just funny that way. However, I also teach my students how to survive these seeming catastrophes, just as I teach them how to survive a failure of their computer, depth gauge, submersible pressure gauge or timing device.

 

[MikeFerrara]

Mike,

You work only in PSI, I integrate minutes as well. I guess it's only useless if you make it so. It's easy enough to see that if I am at 60 feet that I will personally need 9 minutes to ascend. So if I start to the surface with 20 minutes of gas left, there is no way in hell that I don't have enough for me and my buddy.

Now, should I develop some task loading, like doing a search and recovery, where my focus is primarily on finding a lost diver, then I find this incredibly simple to make decisions on the fly. Since I may also be narced, I am using the far more stable circuitry of the computer to help me make these decisions.

But like BCs or the Reg you use, this is ultimately up to your personal preference.

Actually I think more in terms of volume and of course time but that's beside the point. Even if you can back out of "gas time remaining at depth" to find out whether or not you have enough for 2 divers to ascend...why? It's just as easy to get to the same place from pressure or volume remaining and that's more direct (since I know what volume I need). I just don't see what the air integrated feature of the computer is doing for you.

 

[Robert Phillips]

Why would I want to? As Ann Marie pointed out, when EVER you have a primary equipment failure, you simply end the dive.

For myself, and most of the divers I know and dive with, a computer/bottom timer/depth guage is not considered a primary piece of equipment. It is a backup.

Ann Marie's post said "ANY piece of euipment."

 

[CompuDude]

Why would it be useless? It calculates your current SAC at that depth and then it will display the remaining bottom time by what limits you: gas supply or ndl. That it sounds an alarm at a preset limit makes it a valuable fail safe as well.

I can't speak for all computers, but I know my my Uwatec SmartTec I program it with a preset gas limit that it then uses in calculating the remaining bottom time figure. I can specify any amount of gas, 300-3000psi to be held in reserve, and it will show remaining bottom time, including time to ascend at a safe rate, AND hold a safety stop (of a duration I also preset), to end up on the surface with x psi of gas in my tank.

Using a little mental math it's pretty easy to see that if you halve the remaining BT (per the computer) and add in a margin for safety (and increased gas consumption), you should be able to swim two divers up safely.

Like I've said, it's handy for a mental cross-check, but not something I generally follow to the letter, esp. because I have to mentally correct the number it shows to allow for the safety margins (2 divers, etc.) that it doesn't account for. It would be nifty if someone built a computer where you could program it to account for such things, however...

 

[The Chairman]

It's just as easy to get to the same place from pressure or volume remaining and that's more direct (since I know what volume I need). I just don't see what the air integrated feature of the computer is doing for you.

Actually Mike, the gas time remaining will auto adjust for an increased respiration due to exertion, temperature, etc. IOW, it's taking in factors you may or may not recognize as mitigating.

 

[Ann Marie]

For myself, and most of the divers I know and dive with, a computer/bottom timer/depth guage is not considered a primary piece of equipment. It is a backup.

Ann Marie's post said "ANY piece of euipment."

LOL..picky, picky.. I should have said PRIMARY. (For my diving I feel that a computer/bottom timer/depth guage is primary equipment. Primary equipment can also vary depending on environment and conditions.)

...but then you could argue that if a primary piece of equipment broke and you were carrying a redundant piece would you still have to end the dive?....

 

[Robert Phillips]

LOL..picky, picky.. I should have said PRIMARY. (For my diving I feel that a computer/bottom timer/depth guage is primary equipment. Primary equipment can also vary depending on environment and conditions.)

...but then you could argue that if a primary piece of equipment broke and you were carrying a redundant piece would you still have to end the dive?....

My point was that a computer/bottom timer, etc... should not be considered a primary piece of gear. It is a backup for your brain. If you are teaching that a computer is an essential piece of gear, what are you teaching them to use as a backup? Obviously not tables...

If my bottom timer were to die during a dive, I should have a very close approximation to my depth and time as I check every five minutes. If, during the period between the last time I checked andthe point were I find it has failed, I know that five minutes ago I was at x depth at y time. Why would I need to thumb the dive? If I called a turn around at this point and headed back to the entry, I have a damn good idea of how long it will take and what my average depth would be, as I had been keeping track of it for the first half of the dive

Do people stop using tables because they bought a computer and now believe they have no use for them, or did they stop using tables because they found they did not need them because they are useless?

 

[Jorbar1551]

There, I fixed it for you.

You've have the computer for "a couple weeks" and you haven't spent a few minutes to read the manual? Instead of piddling around on scubaboard, go read the manual for your computer.
Your own post proved your point.

Finals, two retail christmas jobs and i didnt think i was going to be diving any time soon is why i didnt read the manual.

 

[neil]

If my bottom timer were to die during a dive, I should have a very close approximation to my depth and time as I check every five minutes. If, during the period between the last time I checked andthe point were I find it has failed, I know that five minutes ago I was at x depth at y time. Why would I need to thumb the dive? If I called a turn around at this point and headed back to the entry, I have a damn good idea of how long it will take and what my average depth would be, as I had been keeping track of it for the first half of the dive

If my computer were to die during a dive, I should have a very close approximation to my depth and time as I check every five minutes. If, during the period between the last time I checked andthe point were I find it has failed, I know that five minutes ago I was at x depth at y time. Why would I need to thumb the dive? If I called a turn around at this point and headed back to the entry, I have a damn good idea of how long it will take and what my average depth would be, as I had been keeping track of it for the first half of the dive.

I have no strong opinion concerning the use of tables vs. computers, but I think your reasoning, or justification is weak.

Do people stop using tables because they bought a computer and now believe they have no use for them, or did they stop using tables because they found they did not need them because they are useless?

The former, I think. I don't think anyone considers tables useless. They don't necessarily make sense as backup to computers, though.