Dive Table

[animian2002]

Hi

I was taught how to use a Dive Table/Padi Recreational Dive Planner when I took my OW in June.

As always, planning dives in advance are encouraged. Taking note of depth, bottom time etc , all that I can understand

But I think I have problem when it comes to multiple dives. The planning, the Dive table and the recording of log book sure make me crazy all that RNT (Residual Nitrogen Time), ABT (Actual Bottom Time) , (PG)Pressure Group etc sure me

As a result of that ;-0 , I have to depends on Friends to work on the figures cos it seem that I'm always out of range when I'm sure that I have dived within the recreational dive limit. Also I don wan to always depend on others.

So my :question: are how do I know I have done the calculation correctly?? and is there a way to check that I'm correct ???

PS: I don have a Dive computer.

Appreciate some advices

Thanks in advance

 

[Uncle Pug]

animian2002 once bubbled...
Appreciate some advices

Thanks in advance

Table tutors:
http://www.aquaholic.com/freesoft.htm
http://www.flash.net/~table/table/p0000065.htm

 

[Ari]

One dive is easy enough to plan using the dive tables. The next ones are not that difficult as weel if you know what you are doing.

Go back to the books and try the excercises. After a number of those you should be OK. Try to plan 3 dives in a row and see where you get.

Ari

 

[animian2002]

Thanks Uncle Pug

the Table Tutors are simply great ...

Now wat I shld do is, to dives more often pactice make prefect

Aso Ari, in my region, we usually do repetitive dives in one diving trip. so I will definitely get chances to practice

thanks for the advices

 

[SubMariner]

Animian, you may want to consider switching from the "flat" Recreational Dive Planner (RDP) to The Wheel.

The Wheel adds in the Residual Nitrogen for you and makes planning multiple dives much easier. It is also the closest you can come to a dive computer without actually buying one, as you can do multi-level dives with it.

Planning multi-level dives with The Wheel will give you more accurate & better down time than the square profile you get with the "flat" RDP.

Hope this helped,

~SubMariner~

 

[JDostal]

To practice, just run through the scenarios available in your book..then come up with new ones to practice on. It's pretty easy once you get the hang of it...

When I first started, I wrote down possible dives just to see if they would work or not. I'll make a dive to 80 for 20 min and then a 2hr SI...now how long can I stay at 60? Just do it for practice and before you know it, it'll be no problem.

The wheel will help you a lot in diving longer w/out a computer - it gives you "credit" for the time you spend at shallower depths...it doesn't assume that you drop down to your depth and stay there for the duration of the dive like the tables do.

 

[jeffsterinsf]

...no, not while diving or driving...

...but most people I have talked with about tables understand the concept of "pacing" while out for an evening of alcoholic beverages. If you constantly end up drunk when you drink, stop here.

Otherwise, you may find it helpful to think of the nitrogen loading like alcohol in your bloodstream. The first table tells you how drunk you are from what you just drank -- or absorbed in the case of nitrogen. Your group letter is an indication of how much is in you at the end of the dive. You might think of the depth as how strong the drink is...

Then you sit back during a surface interval. Much like you would burn off alcohol in your bloodstream, the nitrogen leaves you slowly over time. So, the new group letter represents how much is still in you.

Ooooh -- that third table. Hmmm -- for me, I look at the RNT at a given depth. It is like asking "If I had been in the bar all this time drinking, how much would I have drunk to be this intoxicated?" So I can go back to the first table with the RNT (at the appropriate depth) and have that "count against" me, as if I had already been diving at that depth (or drinking that much in the bar) for that long.

For me, I ignore the adjusted bottom time on my tables and compute it myself. If I can't subtract, I shouldn't be diving

If I decide that I want to dive longer, that means that I need to "be less intoxicated" when I start -- so that means less RNT, which I can get with a longer surface interval (more time to "burn" it off), or less impact (less depth for the next dive).

The analogy isn't perfect, but it has helped some people I've talked with has helped them find a way to understand the tables a bit better.

 

[animian2002]

jeffsterinsf, u have a very unique way of explaining ... but I get wan u meant :gotcha:

SubMariner, If the wheel is the closest subsititute to a dive computer, guess I shld get myself one...

but then I have only seen the wheel in the PADI video , But have not seen it being sold in the DS in my region ;-0 ... guess I have to hunt them down elsewhere