Alternative to the PADI wheel

[alexxred]

Hi,

Using the standard PADI dive table your NDL is taken from 1 depth as a result if your doing a multi level your dive time is limited. Of course the Wheel is the solution to this allowing you to plan a mult level dive. I was just wondering if their is an alternative method or tables that can be used to plan a multi level dive other than the PADI wheel. I do own a computer but would like to further my knowledge in this area.

Thanks

Alex

 

[Dive-aholic]

The table can be used for multilevel dives as well. It's not advised, but if you know enough about the wheel and play around with the 2, you'll see how it works.

 

[kensuguro]

I think it's one of the silliest ideas, but has anyone worked with the electronic RDP? It's the one that looks like a calculator, and is PADI official. Not sure if it does multi-level though..

 

[Dive-aholic]

It's just an electronic version of the RDP. It doesn't do multi-level. It's really nothing more than a dive planner much like on most recreational computers.

 

[Jim Lapenta]

Take the erdp, and insert 1 min for surface interval on a mutil level profile and see what your ending pressure group is. Ie 1stdive? yes depth 80 ndl 30 min,abt 15,pg G,si 1min, pg after G, depth 50, andl 54, abt 20, pg O, si 1 min, pg O, depth 35, andl 126, abt 15, pg R. Now check this with your wheel and see what you get. Above calculations were done with erdp then verified with wheel. It's not suppose to work like this is it? but it does and if you stay well within the the no deco limits the 1 min interval is not pushing it. I would not do this if I was going to stay within a minute or two of the ndl for each leg of the profile. Which of course you should not be doing anyway.

 

[Jim Lapenta]

The table can be used for multilevel dives as well. It's not advised, but if you know enough about the wheel and play around with the 2, you'll see how it works.

Yep! Just takes a little patience and time.

 

[StSomewhere]

See this related thread:

http://www.scubaboard.com/showthread.php?p=1312824#post1312824

And maybe this one too:

http://www.scubaboard.com/showthread.php?t=78882&highlight=Flat+Wheel

 

[Charlie99]

Take the erdp, and insert 1 min for surface interval on a mutil level profile and see what your ending pressure group is. Ie 1stdive? yes depth 80 ndl 30 min,abt 15,pg G,si 1min, pg after G, depth 50, andl 54, abt 20, pg O, si 1 min, pg O, depth 35, andl 126, abt 15, pg R. Now check this with your wheel and see what you get. Above calculations were done with erdp then verified with wheel. It's not suppose to work like this is it? but it does and if you stay well within the the no deco limits the 1 min interval is not pushing it.

Both the wheel and the rdp are based upon the same underlying model, so it shouldn't be a surprise that you get results like you see.

The wheel, though has a couple additions called "ML limits" and also limits on the allowable combinations of depths for the profiles, along with a bunch of other miscellaneous rules (For example with RDP a 3 min safety stop is require if within 3 PG of NDL. With the wheel, the stop becomes required if with 3 PG of the ML limit.

The other interesting thing in comparing the wheel and the RDP is that the wheel has just one scale for calculating PG changes during the SI, while the RDP has zillions of tiny numbers in the SI table. If you look a bit more closely at the RDP SI numbers, you realize that it can be replaced with just on series of numbers if you are willing to just add SI minutes to a beginning number for your starting PG.

My Flat Wheel, also based on the PADI/DSAT 60 minute compartment, is kind of a combination of the PADI RDP and Wheel.

 

[Charlie99]

I was just wondering if their is an alternative method or tables that can be used to plan a multi level dive other than the PADI wheel.

Some divers simply keep track of the average depth of their dive, and keep their time and average within either table limits or a simple "avg depth + time" < 120 or 110 minutes.

This algorithm allows dives that are beyond NDL as calculated with either the PADI/DSAT algorithm or the Buhlmann algorithm, and although it is hinted at by some instructors, I don't believe it is actually taught by any reputable agency.

 

[in_cavediver]

Hi,

Using the standard PADI dive table your NDL is taken from 1 depth as a result if your doing a multi level your dive time is limited. Of course the Wheel is the solution to this allowing you to plan a mult level dive. I was just wondering if their is an alternative method or tables that can be used to plan a multi level dive other than the PADI wheel. I do own a computer but would like to further my knowledge in this area.

Thanks

Alex

There is always custom cut dive tables. These are most often associated with tec diving but can work just the same in rec diving. There are a lot of free versions out there and they all can do just what you ask. (with a laptop or palm, they do repetive dives too!)

Mike