Dekoplaner - plan, share, dive!

What began as my personal programming project is now available to everyone: Dekoplaner — a dive planner from Switzerland based on the Bühlmann ZHL-16C model, the globally established standard for decompression calculations.

Dekoplaner deliberately focuses on the essentials: transparent and easy-to-understand calculations using classic gradient factors (GF low / GF high)—without unnecessary additional parameters.

Dekoplaner is a powerful yet affordable all-rounder for planning dives with SCUBA and CCR using up to three decompression gases, as well as multilevel and bailout options.

Thanks to the integrated gas mixer, Nitrox and Trimix mixtures can be calculated easily and reliably. This allows Dekoplaner to be used to plan a dive from gas planning through to decompression.

Dekoplaner — now available on the Play Store.

The Idea Behind Dekoplaner

Many planning programs offer a large number of additional models, adjustments, and parameters. This leads to greater complexity, usually without any added benefit.

Dekoplaner takes a different approach:

• Only the necessary parameters.

• No hidden model adjustments.

• No opaque additional assumptions.

What is calculated is transparent. And what is not implemented is unnecessary.

This approach makes the planner suitable for ALL divers, but especially for technically oriented divers, instructors, and training purposes.

The Deco Planner covers all essential requirements of modern dive planning.

Gas and Dive Planning

• OC planning with any gas mixtures (air, nitrox, trimix)

• CCR planning with freely selectable diluent and O₂ setpoint

• 3 decompression gases with automatic sorting and switch depths at pO₂ 1.6 bar

• Multilevel profiles with any number of depth segments

• Bailout calculation in CCR mode

Display and export

A dive plan is only as good as its documentation. The Deco Planner offers:

• Graphical dive profile

• Export as TXT

• Export as PNG

• Export as PDF

This makes it easy to archive dives, share them, or use them for training purposes.

Plan. Share. Dive.

Calculation Logic – How the Dekpoplaner Works

A key feature of the Dekoplaner is its calculation method. Decompression is not simulated prospectively, but is calculated every second starting from the beginning of the decompression phase. A data point is generated for every second of the dive—similar to how a modern dive computer operates. In the run plan, all times are rounded up for safety reasons.

The actual decompression calculation begins only after the entered dive profile has been completed.

Rates of descent and ascent

The standard rates are:

• 20 m/min descent

• 10 m/min ascent

CCR Mode

In CCR mode, the calculation follows a clearly defined setpoint logic:

• Up to a depth of 6 m, the calculation uses the selected O₂ setpoint

• Above 6 m, the calculation uses a safety setpoint of 0.7 bar

If the setpoint is exceeded, the calculation becomes diluent-limited.

This approach corresponds to a conservative and technically verifiable modeling of CCR profiles.

High-altitude dives

The Deco Planner also supports high-altitude dives. In this case:

• calculations are based on the current ambient pressure

• the initial state is conservatively assumed to be tissue equilibrium at sea level

• no acclimatization is assumed

This approach is deliberately conservative.

Application of the Model

The gradient factors are applied in the classical manner. The supersaturation tolerances are linearly interpolated between GF low and GF high.

For trimix, the tissue parameters are continuously adjusted according to the current gas composition.

In addition to decompression calculations, the Decoplaner provides further important information.

Gas consumption

Gas volume is calculated using Minute ventilation (MV) 20 l/min

This allows for a quick estimate of the required gas reserves.

Gas density

Gas density is calculated, and the following occurs:

• a warning is issued at > 6.2 g/l

High gas densities represent a significant risk factor for hypercapnia (CO2 poisoning) and should be taken into account during planning.

CNS toxicity

CNS toxicity is calculated according to the current NOAA tables.

The new NOAA CCR recommendations, which have not yet been ratified, have been deliberately not implemented.

Limitations – Deliberately Transparent

No planner can assume responsibility—this also applies to the decompression planner. Profiles that are nonsensical or physiologically problematic can, in principle, be entered.

In the event of limit violations:

• pO₂ exceedances or undershoots

• pN₂ exceedances

warning messages are displayed. However, the calculation itself is still performed.

This also applies if the CCR cannot maintain the pO₂ setpoint due to an excessively high O₂ concentration in the diluent.

The choice of a sensible and safe dive profile remains the sole responsibility of the user.

The Gas Mixer

Thanks to the integrated gas mixer, even challenging dives can be planned with ease—from creating the gas mixture to complete decompression planning with the Decoplaner.

Starting from any initial mixture, this function provides precise instructions for preparing Nitrox and Trimix mixtures of any kind. In addition to oxygen, helium, and compressed air, other filling gases can also be used (e.g. EAN 32).

The calculation is based on the Van der Waals equation, thereby enabling the most precise determination possible of the required gas proportions. Optionally, a top-up calculation can also be performed with a freely selectable filling gas.

Units and Languages

The Decoplaner can be used in either German or English. Additionally, it supports both metric units (bar, meters) and imperial units (psi, feet), allowing for flexible use in different regions and training environments.