Disclaimer¶

Planning calculator only¶

AeroPlus Deco is a planning calculator. It performs decompression and gas calculations to help you prepare a dive plan before entering the water. It is not a dive computer and cannot be used during the dive itself — divers must use a certified dive computer for in-water decompression management.

Always verify calculations against a second planning source — another planning tool, a dive computer simulation, or a qualified instructor — before relying on them. If the second source disagrees, find out why before you dive.

What the software does¶

AeroPlus Deco implements the Bühlmann ZHL-16C algorithm with gradient factors — a well-established, widely used dissolved-gas decompression model. The calculations cover:

Decompression schedules for open-circuit and closed-circuit rebreather profiles
Gas mix planning (best mix, MOD/EAD/END, density)
Gas consumption, reserves, and rock-bottom calculations
CNS and OTU oxygen-exposure totals
Partial-pressure gas blending

All calculations are based on standard published formulas and inputs you provide. The accuracy of the output depends entirely on the accuracy of those inputs.

What the software does not do¶

It does not measure depth, time, or pressure during a dive
It does not provide live decompression guidance underwater
It does not communicate with diving equipment
It does not diagnose, monitor, treat, or compensate for any medical condition
It is not a substitute for diver training, certification, or professional instruction

No warranty¶

AeroPlus Deco is provided "as is", without warranty of any kind — express or implied — including without limitation any warranty of merchantability, fitness for a particular purpose, or non-infringement. The authors and publisher disclaim all liability for any damages arising from the use or misuse of the software.

By using this software you accept full responsibility for your own diving decisions and acknowledge that the planning output is one input into your decision-making, not a substitute for proper training, equipment, and judgement.

Not a substitute for training¶

This documentation explains what the calculator does and how to use it. It does not teach you to dive. Technical diving — including decompression diving, trimix, and rebreather diving — requires:

Certification by a recognised training agency (TDI, IANTD, GUE, PSAI, NAUI Tec, RAID, etc.)
Supervised, progressive in-water training
Mentored experience under qualified instructors
Ongoing skill maintenance and currency

If you don't hold the certifications appropriate to the dive you're planning, don't dive it. Use AeroPlus Deco for study, comparison, or to prepare for training — not to enable diving you aren't qualified for.

Garbage in, garbage out¶

The gas calculations in AeroPlus Deco — rock bottom, gas plan, bailout sufficiency — are based on inputs you provide (SAC rates, cylinder sizes, fills, emergency rates). Wrong inputs produce wrong outputs. Confirm:

Cylinder size matches your physical tank (steel vs aluminium, nominal vs actual volume)
Fill pressure matches the actual gauge reading
SAC rate reflects your real-world consumption on the dive type you're planning
Mix percentages match what was analyzed in the cylinder

Always analyze your gas with a calibrated O₂ analyzer (and helium analyzer for trimix) before diving. Label cylinders, and follow your team's gas-matching protocol before the dive.

CCR specifics¶

Closed-circuit rebreather diving is significantly more complex than open circuit. The CCR planning features assume:

Correct setpoint values entered for your unit
Bailout cylinders appropriate for your unit and dive plan
A trained, current CCR diver operating the unit

Oxygen consumption and scrubber endurance are not calculated by the app. Managing your O₂ supply and absorbent duration is entirely yours — either can end a dive well before your bailout gas or decompression obligation does.

The bailout sufficiency check is a calculation, not a complete validation — it does not verify that you have the right type of gas for the depth ranges involved, only that the volume is sufficient. Verify mix compatibility manually.

Model conservatism¶

Gradient factors are personal. The defaults (GF 50/75) are a modern starting point but not universally appropriate. Choose conservatism based on:

Your training and your agency's guidance
Your personal history and physical factors
Conditions (water temperature, current, exertion expected)
Time since last dive and recent fatigue
Hydration, sleep, and general fitness on the day

If in doubt, be more conservative, not less.

Updates and version stability¶

This software is under active development. Algorithms, defaults, and UI may change between versions. The version displayed in the app header is your reference for any issue report. Plans saved from older versions should re-import into newer versions, but always verify the output looks correct after an update.

Reporting issues¶

If you find a bug, an incorrect calculation, or a regression:

Use Help & feedback in the app to email support@aeroplus-deco.com
Include the plan share link, browser, version, and a description of what you observed vs expected

Issues affecting calculation correctness are triaged with priority.

Privacy¶

AeroPlus Deco does not collect personal data, analytics, or telemetry. Your plans, settings, and license details stay on your device unless you explicitly share them via a link, PDF, or JSON export.

Network requests are made only:

To load the app initially (sjjan.github.io)
To activate or deactivate a license (api.polar.sh)
When you click external links (e.g. references in the About page)

Copyright¶

Documentation © Magnolia Blossom BV. The source text of this documentation may be reproduced for personal study; redistribution requires permission.

The Bühlmann ZHL-16C algorithm is in the public domain (Bühlmann, Tauchmedizin). The gradient factor extension is attributed to Erik C. Baker.

Contact¶

Email: support@aeroplus-deco.com

Bug reports & feature requests: github.com/sjjan/aeroplus-deco/issues

By using AeroPlus Deco, you acknowledge that you have read and understood this disclaimer and accept responsibility for your own diving decisions.