Nitrox Essentiels

Nitrox Essentiels is a compact, field-ready toolkit that helps Nitrox divers prepare, verify and explain gas planning and limits before and during diving operations. Nitrox Essentiels guides users through single-dive calculations, mix preparation and multi-profile day planning using clear inputs for FO2, target depths and maximum PpO2; it then produces PMU/MOD values, optimal mix suggestions and refill modelling so divers can review options quickly and reliably.

Key features and calculations

The app performs PMU and MOD calculations from FO2 and a maximum allowed PpO2 and presents safe depth limits in plain language. It computes an optimal Nitrox mix for a selected target depth, then models refills by simulating additions of pure oxygen or air with optional air dilution, returning expected tank FO2 and usable depth. An O2 plan tool compares an air profile with a Nitrox alternative for each dive, highlights which Nitrox would be recommended for the first stop, and tracks cumulative CNS and OTU values. Every calculation can be saved to a plan history for later review and comparison, and diver initials are stored locally so repeated users can review consistent records.

How it works: controls and workflow

The interface keeps controls straightforward: numeric fields for depth, gas fractions and pressure; pickers for unit systems (meters/feet, bar/psi); and simple selectors for maximum PpO2 and mix targets. Calculation details can be toggled on in training mode so learners see intermediate steps, formulas and assumptions rather than only final numbers. Typical workflow is: enter diver profile and units, select or enter FO2 and target depth, run PMU/MOD and mix calculations, then save the plan or simulate a refill. All operations are executed locally and require no network connection.

Training, progression and practice

Nitrox Essentiels includes a training mode intended for trainees and instructors who want to review the underlying math and teach decision-making. Training mode reveals calculation steps and key safety checks so users can progress from understanding concepts to verifying their own planning work. Progression is informal and self-directed: users develop proficiency by creating practice profiles, reviewing plan histories, adjusting parameters and re-running scenarios to observe how FO2, depth and PpO2 interact. Saved profiles and repeated use help build a personal reference library of common mixes and typical day plans.

Visual style, accessibility and customization

The app favors a clear, uncluttered layout optimized for field use with readable type, high contrast elements and both light and dark themes to improve visibility underwater or in bright sunlight. Units and display preferences are configurable so users can work in the measurement system they trained with. The interface is designed to be accessible: controls use large tappable areas, input fields accept either decimal or whole-number formats, and important warnings are highlighted to draw attention. Preferences and diver initials are stored locally and can be edited at any time.

Offline play, reliability and data handling

Nitrox Essentiels is fully functional offline: all calculators, history storage and profile management run without network access to ensure reliable use on boats or remote sites. Data is stored on the device and can be cleared by the user; the app does not depend on cloud services or online verification to produce results. Because calculations are deterministic and fast, the app is battery-friendly and suitable for quick checks on the surface between dives.

Challenge systems, replay value and practical use

Replay value comes from scenario practice and the ability to create varying day plans and refill strategies to explore how small parameter changes affect safety margins. The practical challenge is in planning efficient mixes and refills while staying within CNS/OTU and PpO2 limits; repeating scenarios with different constraints builds practical judgment. The plan history supports comparison across sessions so divers can review how approaches evolved and which mixes were most efficient for particular dive profiles.

Safety notes and limitations

This application is a calculation and planning aid only and does not replace formal dive training, your organization’s procedures, certified gas analysis tools, official dive tables, or a dive computer. Always verify actual gas contents with an analyzer and follow your training, agency guidance and local regulations. The developer and this description do not assume responsibility for dive planning decisions; Nitrox Essentiels is intended to support trained or supervised divers in understanding and reviewing their plans.