DDPLAN

The Drogon Dive Planner

Copyright © 1999 - 2001 Gordon Henderson

Some Features:

  • Algorithm: Standard Buhlmann with ZH-L16 Helium table and ZH-L16b Nitrogen table
  • Compartment 1b is used for compartment 1.
  • Alveolar water vapour pressure is (optionally) considered.
  • The Schreiner equation is used to calculate the ascent and descent portions of the profile with the Haledane steady state equation used in constant depth sections resulting in extremely fast calculation times.
  • Deep stops: Erik Bakers gradient profile method.
  • Equipment support: Open circuit and Closed circuit (constant ppO2) SCUBA equipment is catered for. The software can switch from closed circuit to open circuit at any point to facilitate bail-out planning.
  • Gas Selection: 8 different gas sets can be specified for decompression in addition to travel gases specified in the dive profile. (Each gas-set can have up to 6 gases in it, each with a switch-over depth setting)
  • The gas-sets can be used in open circuit mode to signal a gas change on the ascent, or in closed circuit mode to specify a diluent change on the ascent.
  • Closed Circuit use: Up to 8 decompression Oxygen partial pressure settings. (Each set contains up to 6 setpoints, each with a switch-over depth setting)
  • Table Generation: DDPLAN can automatically generate tables over a given depth range for a given range of times. Rebreather bail-out (ie. going to open circuit from closed circuit) tables can also be generated.
  • Interface: Text/Screen based. No Windows or mouse required.
  • CNS and OTU tracking: CNS and OTUs are calculated for each different gas switch or each setpoint you select in closed circuit mode.
  • Open Circuit Gas consumption: You can set gas consumption for the ``working'' part of the dive and the decompression stages and DDPLAN will work out your total gas required.
  • Gas Calculations: DDPLAN Contains some useful gas calculation software for filling cylinders and working out various partial pressures of gases at depths. It features the Mix-a-Matic to enable you to fiddle with depth, Oxygen and Helium percentages interactively.
  • Units: Metric units only. I have no plans to make a version which uses imperial units (sometimes called "English" units, by the Americans, but I can't figure out why as here in England we've been using the metric system for more years than I care to remember!)

Features possibly lacking:

  • Gases other than Oxygen, Helium and Nitrogen.
  • Air (or other gas) breaks on long 100% O2 decompression stops.
  • Altitude diving.
  • Anything else you'd like to see, but can't find it in the software (yet!)

Go back to the main menu, or forward to DDPLAN installation or read on for...

Screen Shots

The main menu screen:

 The Drogon Dive Planner           Main Menu                              v2.15 

          The Drogon Dive Planner
        http://www.drogon.net/ddplan
      Copyright (c) 1999-2001 Gordon Henderson


    D. Plan a dive.

    G. Perform various gas calculations
    F. Perform various cylinder filling calculations


    Q. Quit.

  Choose D, G, F or Q: 

The edit screen showing a dive to 40m for 30 minutes (run-time) on air:

 The Drogon Dive Planner       Edit Dive Profile                          v2.15 

  Step   Depth   Time    Gas           Type   ppO2  ppHe  ppN2   END 
   1    0-> 40   1:20    Air            OC    1.05  0.00  3.95    40
   2        40  30:00(R) Air            OC    1.05  0.00  3.95    40

The run-output from the above dive. Decompressing solely on air with the last stop being performed at 6m, using the default Gradient Factors of 30/75:

 The Drogon Dive Planner           [default]                              v2.15 

    The Drogon Dive Planner [v2:13]
========================================

Dive profile for default:
 Step   Depth      SegT   RunT        Gas           ppO2  END
===============================================================
  1   0.0-> 40.0   1:20   1:20        Air           1.05   40
  2  40.0-> 40.0  28:40  30:00        Air           1.05   40

Deepest effective stop: 27m
Buhlmann + Gradient Factor decompression schedule:
 Step   Depth      SegT   RunT   %MV  Gas           ppO2  END
===============================================================
  3  40.0-> 21.0   3:00  33:00  63.4  Air           0.65   21
  4  21.0-> 18.0   1:00  34:00  67.6  Air           0.59   18
  5  18.0-> 15.0   2:00  36:00  72.7  Air           0.53   15
  6  15.0-> 12.0   5:00  41:00  77.2  Air           0.46   12
  7  12.0->  9.0   7:00  48:00  80.8  Air           0.40    9
  8   9.0->  6.0  55:00 103:00  82.8  Air           0.34    6
  9   6.0->  0.0   0:36 103:36  90.0
===============================================================
           Dive time:  0:30:00    Gradient Factors were used:
  Ascent & Deco time:  1:13:36      Low factor:   30%
                      ========      High factor:  75%
      Total run time:  1:43:36

  Ascent rate: 10, Descent rate: 30 (m/min)  Total CNS: 12%  OTUs: 34

      OC Gases used:
    Depth  Gas           ppO2 END  MOD   Litres   CNS
  =====================================================
        *                                  5043   11.8  OC CNS Total: 12%

The same run, this time decompressing on 50% and 100%.

    The Drogon Dive Planner [v2:13]
========================================

Dive profile for default:
 Step   Depth      SegT   RunT        Gas           ppO2  END
===============================================================
  1   0.0-> 40.0   1:20   1:20        Air           1.05   40
  2  40.0-> 40.0  28:40  30:00        Air           1.05   40

Deepest effective stop: 27m
Buhlmann + Gradient Factor decompression schedule:
 Step   Depth      SegT   RunT   %MV  Gas           ppO2  END
===============================================================
  3  40.0-> 21.0   3:00  33:00  63.4  Nitrox 50     1.55   10
  4  21.0-> 18.0   1:00  34:00  66.2  Nitrox 50     1.40    8
  5  18.0-> 15.0   1:00  35:00  70.3  Nitrox 50     1.25    6
  6  15.0-> 12.0   2:00  37:00  75.5  Nitrox 50     1.10    4
  7  12.0->  9.0   5:00  42:00  80.8  Nitrox 50     0.95    2
  8   9.0->  6.0  12:00  54:00  81.8  Oxygen        1.60    0
  9   6.0->  0.0   0:36  54:36  87.7
===============================================================
           Dive time:  0:30:00    Gradient Factors were used:
  Ascent & Deco time:  0:24:36      Low factor:   30%
                      ========      High factor:  75%
      Total run time:  0:54:36

  Ascent rate: 10, Descent rate: 30 (m/min)  Total CNS: 43%  OTUs: 69

      OC Gases used:
    Depth  Gas           ppO2 END  MOD   Litres   CNS
  =====================================================
        *                                  2791   11.3
       21  Nitrox 50     1.55   10   22     347    5.0
        6  Oxygen        1.60    0    6     293   26.3  OC CNS Total: 43%

Now, a table for this 40m dive, from 10 minutes to 45 minutes, using 50% and 100% for decompression.
  40m   default   40m  
Gas ppO2 D\RT 10 15 20 25 30 35 40 45
Nx 50   21 2/ 12 2/ 17 2/ 22 2/ 27 3/ 33 3/ 38 3/ 43 4/ 49
Nx 50   18     2/ 24 2/ 29 1/ 34 1/ 39 2/ 45 1/ 50
Nx 50   15   2/ 19 1/ 25 1/ 30 1/ 35 2/ 41 2/ 47 4/ 54
Nx 50   12 2/ 14 1/ 20 1/ 26 1/ 31 2/ 37 4/ 45 4/ 51 4/ 58
Nx 50   9 1/ 15 1/ 21 1/ 27 3/ 34 5/ 42 4/ 49 6/ 57 7/ 65
Oxy   6 1/ 16 4/ 25 7/ 34 9/ 43 12/ 54 15/ 64 18/ 75 21/ 86
CNS% 7 16 26 33 43 52 62 72
    DDPLAN v2.15   Gradient Factors: 30/75      

Now, something a little more complicated.
A closed circuit Trimix dive to 70m for 20 minutes, bailing out to open circuit gas.
We have 10/50 diluent, 16/40 Trimix and 50% Nitrox and 100% O2 bail-out gases.
The Editor screen:

  Step   Depth   Time    Gas           Type   ppO2  ppHe  ppN2   END 
   1    0-> 70   2:20    Trimix 10/50   CC    0.70  4.06  3.24    31
   2        70  20:00(R) Trimix 10/50   CC    1.30  3.72  2.98    28
   3        70   0:00(S) Trimix 16/40   OC    1.28  3.20  3.52    35

And the run output:
(Note that the gas listed in the run output (9/51 and 16/47) represents the theoretical
loop gas of the rebreather when adjusted for the selected setpoint)

    The Drogon Dive Planner [v2:13]
========================================

Dive profile for default:
 Step   Depth      SegT   RunT        Gas           ppO2  END
===============================================================
  1   0.0-> 70.0   2:20   2:20        Trimix  9/51  0.70   31
  2  70.0-> 70.0  17:40  20:00        Trimix 16/47  1.30   28
  3  70.0-> 70.0   0:00  20:00        Trimix 16/40  1.28   35

Deepest effective stop: 54m
Buhlmann + Gradient Factor decompression schedule:
 Step   Depth      SegT   RunT   %MV  Gas           ppO2  END
===============================================================
  4  70.0-> 36.0   5:00  25:00  67.7  Trimix 16/40  0.74   16
  5  36.0-> 33.0   1:00  26:00  69.2  Trimix 16/40  0.69   14
  6  33.0-> 30.0   1:00  27:00  72.1  Trimix 16/40  0.64   12
  7  30.0-> 27.0   2:00  29:00  75.3  Trimix 16/40  0.59   11
  8  27.0-> 24.0   2:00  31:00  77.0  Trimix 16/40  0.54    9
  9  24.0-> 21.0   2:00  33:00  79.2  Nitrox 50     1.55   10
 10  21.0-> 18.0   2:00  35:00  80.0  Nitrox 50     1.40    8
 11  18.0-> 15.0   3:00  38:00  82.2  Nitrox 50     1.25    6
 12  15.0-> 12.0   5:00  43:00  84.6  Nitrox 50     1.10    4
 13  12.0->  9.0   7:00  50:00  85.2  Nitrox 50     0.95    2
 14   9.0->  6.0  24:00  74:00  87.0  Oxygen        1.60    0
 15   6.0->  0.0   0:36  74:36  90.3
===============================================================
           Dive time:  0:20:00    Gradient Factors were used:
  Ascent & Deco time:  0:54:36      Low factor:   30%
                      ========      High factor:  75%
      Total run time:  1:14:36

  Ascent rate: 10, Descent rate: 30 (m/min)  Total CNS: 75%  OTUs: 103

      OC Gases used (or CC diluent switches):
    Depth  Gas           ppO2 END  MOD   Litres   CNS
  =====================================================
        *                                   945    2.4
       21  Nitrox 50     1.55   10   22     648    9.3 
        6  Oxygen        1.60    0    6     581   53.0  OC CNS Total: 65%

      CC Setpoints used:
    Depth   Setpoint   CNS
  ==========================
        *              10.2  CC CNS Total: 10%

Go back to the main menu, or forward to DDPLAN installation.


Gordon Henderson