eRDPml

[TMHeimer]

I just signed up for DM course and got the eRDPml. ML means multi-level. Dive computers track your theoretical N levels as they are with you on the dive. To do anything helpfull with the eRDPml that improves upon the tables, you must keep fairly strict track of all you minutes at various levels during the dive (slate, I guess). That's what computers are for, no? I guess if your computer fails there could be some advantage to having the eRDPml. But the "ML" still gets me. It's also curious that PADI now sells you this device instead of The Wheel but the Diving Knowledge Workbook contains "Wheel" problems and no reference to the new thing.

 

[Joe-Diver]

The documentation has not yet caught up. There will be new editions soon enough.

The eRDPml is a dive planning tool. Use it to plan your dives, not track them after the fact.

 

[knotical]

To do anything helpfull with the eRDPml that improves upon the tables, you must keep fairly strict track of all you minutes at various levels during the dive (slate, I guess).

I don't see how keeping track minute-by-minute would help. The eRDPML acts as either flat tables or the wheel. When used as the wheel, it still requires that your second level be a minimum number of feet shallower than the last depth, for a maximum of four depths.
< edit: - Perhaps I misunderstand your statement. Keeping track of various depths is an additional task that is necessary whether using the Wheel, or the eRDPML in the multi-level mode. >

When used as a flat table, there is one minor improvement. The depths are now rounded up in five foot increments instead of ten, presumably to make it similar to the wheel and to simplify design. That caused a few Knowledge Review and Quiz/Exam answers to be changed slightly.

The main advantages of eRDPs are less likelihood of mistakenly changing rows or columns as you move your finger along the narrow sets of numbers, and not having to do the math of adding RNT to ABT. Big whoop! And some people just find them easier to learn.

It's also curious that PADI now sells you this device instead of The Wheel but the Diving Knowledge Workbook contains "Wheel" problems and no reference to the new thing.

The Diving Knowledge Workbook also contains table problems. To differentiate with the eRDPML, you simply answer "yes" or "no" when you are asked whether it is a multilevel dive.

 

[TMHeimer]

Thanks guys. I now thoroughly understand the eRDPml. A really good planning device--not possible to plan multi-level dives with the RDP tables. I guess you could use it to plan the ml dive if you know your planned depths. If you don't, you can just go and depend on the dive computer and all it's info. I assume if your computer craps out say after the first dive you will have the dive watch on as a back-up and know your minutes at max depth (assuming you look at the watch), and can continue diving (if you haven't excedded the NDL on the first dive) with a repetitive dive using max depths only and the RDP or eRDPml? As time goes by I'm sure I'll have more questions.

 

[Joe-Diver]

Actually you could plan a multi-level with the RDP, but it wasn't designed for it.

If it's your first dive, or you know your PG at the end of the dive before the computer went whack, you could continue to dive on the tables and a watch. As long as you've been tracking your max depth and time, and as long as you haven't gone outside the model, as a computer will allow you to do compared to square profiles with the tables.

 

[TMHeimer]

Yeah, I've read about using the RDP for ML dives, but the computer elliminates the more complicated calculations. So, I guess the eRDPml allows you to do this if you don't use a computer.

 

[Joe-Diver]

While I've done dive planning of square profiles on a dive computer, I'm not aware of any that will allow multi-level planning.

Please remember that your dive planning tools, the RDP, eRDPml and a dive computer for square profiles, are for planning dives. A dive computer is for tracking the dive itself, during the dive, accounting for various times at various depths in detail. So, two very different uses for the tools.

 

[String]

Certainly all the Suunto range will allow multi level planning with the simulation mode so that covers about half the computers world wide for starters.

I hate the eRDPML - a complete abortion of an idea that replaces a complete abortion of an idea (the wheel). Wonder when the eRDL-ML-EAN will be out.

 

[TMHeimer]

Joe, Yeah, I know the computer is for tracking exactly where you've dived and can't be used to plan a dive because it doesn't know where you'll go. I haven't used the computer much yet (was a watch & depth gauge guy), but I imagine that after the first dive you can take the info. from the computer and use that to possibly alter your planning for the 2nd dive using the eRDPml, no? I guess that up to this point (125 dives), I really haven't done any true multi level dives, as I'm usually on the bottom except for very minor depth changes.

 

[Joe-Diver]

I'll have to try the simulation mode....I've only used it in plan mode.