OVM Dive Planner is an iOS dive-planning app for open-circuit and CCR dives.
It calculates decompression schedules using a Bühlmann ZH-L16C model with
gradient factors and includes gas planning tools such as deco gas handling,
repetitive-dive carry-over, and a gas mixer.
Disclaimer
This software is provided on an "as-is" basis without warranty of any kind, express or implied.
The developers and distributors assume no liability for any injuries, damages, or losses resulting from the use of this software.
This app is a mathematical planning tool based on theoretical decompression models. It does not account for individual variations in physiology, metabolism, or decompression sickness susceptibility.
The app does not assess your physical fitness, health status, or medical conditions that may affect diving safety. Consult a dive medicine physician before diving if you have any health concerns.
The app does not evaluate your mental or psychological state, including fatigue, stress, anxiety, or alertness. You must ensure you are physically and mentally fit before diving.
The app does not account for environmental conditions such as water temperature, visibility, currents, weather, sea state, bottom composition, or other site-specific hazards.
The app does not consider your experience level, familiarity with your equipment, or your proficiency with the planned dive profile.
The app does not monitor actual underwater conditions, your real-time physiological state, or equipment performance during the dive.
Decompression calculations are theoretical approximations. Real-world physiology varies significantly between individuals. Follow conservative dive practices and your dive computer.
Diving is an inherently dangerous activity that requires proper training, certification, and appropriate equipment.
You must obtain formal training and certification from qualified instructors before diving.
You must use appropriate equipment and materials for the specific dive profile you intend to execute.
A functioning dive computer is mandatory for all dives and must be used as your primary depth and time reference.
The user assumes all responsibility and risk associated with diving activities and the use of this software.
Safety Notice
OVM Dive Planner is a planning aid only and does not replace professional judgment, formal training,
formalized dive procedures, or real-time in-water monitoring with a dive computer. All dive plans
must be independently reviewed and verified by qualified, experienced divers before execution.
1. App Overview
The app is organized into four main tabs:
Plan
Create the dive profile, select circuit type, assign bottom gas and deco gases, and calculate the dive.
Schedule
Review the decompression schedule, runtime, gas usage, CNS, OTU, and warnings.
Mixer
Use the gas mixer tools for pressure transfer, top-off blending, and trimix fill calculations.
Settings
Configure units, water type, rates, SAC, gradient factors, last stop depth, and other planner defaults.
2. Planning a Dive
Open the Plan tab.
Select Open Circuit or CCR in the Circuit section.
Choose a planning mode:
Visual for chart-based waypoint editing
List for discrete depth/time levels
Enter the dive profile.
Select the bottom gas or diluent.
Add any deco gases if required.
Tap Plan Dive.
The planner supports:
multi-level profiles
trimix and helium-based gases
automatic or manual deco gas switch depths
metric and imperial units
persistent planner settings between launches
3. Using the Visual Planner
The visual planner is the default planning mode.
The vertical axis represents depth, with the surface at the top.
The horizontal axis represents runtime.
Tap the chart to add a new waypoint.
Drag a waypoint vertically to change depth.
Adjust hold time using the waypoint controls below the chart.
The chart expands automatically as the profile grows in depth or time.
List Planner
If you switch to List mode, each level is entered as a depth and time pair.
Both list and visual modes edit the same underlying dive profile.
4. Reading the Schedule
After calculation, the Schedule tab shows:
Max Depth
Bottom Runtime
Total Runtime
Total Stop Time
First Stop
Average Depth
CNS%
OTU
The schedule also includes:
a table of decompression stops
runtime at each stop
planned gas for each stop
estimated gas usage by mix
If the dive does not require decompression, the schedule will explicitly state
No decompression required.
5. Settings
The Settings tab controls global planner behavior.
Units: Metric or Imperial
Water Type: Salt or Fresh
Surface Pressure
GF Low / GF High
Descent Rate / Ascent Rate
Bottom SAC / Deco SAC
Last Stop Depth
Descent Time Included in Bottom Time
CCR Settings
If CCR is selected in the planner, a separate CCR settings sheet is available for:
low setpoint
high setpoint
deco setpoint
switch depth to the high setpoint
CCR bailout/deco gases
Settings are stored between launches.
6. Repetitive Dives
The planner can model a second dive after a surface interval.
Expand the Repetitive Dive section in the planner.
Enable repetitive-dive mode.
Enter the surface interval.
Define the second dive profile and gases.
Calculate the plan.
The app carries tissue loading, CNS, and OTU from the first dive into the second dive calculation.
7. Gas Mixer
The Mixer tab contains three calculators:
Tank Fill (Boost)
Calculates the final pressure after transferring gas from a donor tank into a target tank.
Top-Off Blend
Calculates the final mix after topping off a starting mix with a chosen fill gas.
Trimix Mix
Calculates required oxygen, helium, and air pressures to produce a target trimix.
8. Warnings and Validation
The app displays warnings for conditions such as:
bottom gas ppO₂ above the warning threshold
hypoxic bottom mix at the surface
deco gas switch depths that exceed the configured ppO₂ limit
very long stop conditions or unresolved ceilings
Warnings appear in the schedule view. They are intended to flag conditions that require review before the plan is used. Adjust your plan accordingly before the dive. Do not dive beyond your training and material limits
9. Practical Tips
Review all gas fractions and switch depths before calculating.
Use the visual planner for quick profile shaping and the list planner for precise level entry.
Check CNS, OTU, and gas usage on every decompression dive.
Verify repetitive-dive settings carefully, especially surface interval and second-dive gases.
Re-check settings after switching between metric and imperial units.
Use the mixer tools separately from the planner when preparing gas fills.