# ZDIVE - Dive Tracker & Analysis for Apple Watch & iOS

> ZDIVE is a professional dive tracking, decompression planning, and dive logging application for iOS (17.6+) and watchOS (10.6+), developed by ZYork Software LLC. It turns your Apple Watch and Apple Watch Ultra into a dive companion with Bühlmann ZH-L16C decompression algorithms, sensor tracking, dive log analysis, breathing exercise training, and multi-day trip planning.

- Website: https://zdive.app
- App Store: https://apps.apple.com/us/app/zdive/id6742788878
- Developer: ZYork Software LLC (https://zyork.dev)
- Contact: dive@zyork.dev
- Full Documentation & Technical Specs: https://zdive.app/llms-full.txt

## Key Capabilities & Features

- **Decompression Algorithm**: Bühlmann ZH-L16C with 16 tissue compartments (half-times from 4 to 635 minutes) and configurable gradient factors (GF Low / GF High), supporting repetitive dives and altitude diving adjustments. Also supports VPM-B and RGBM models.
- **Apple Watch & Ultra Integration**: Real-time water submersion detection (watchOS 10.6+), digital crown controls, water lock integration, WR100 rating compatibility, and operating temperature range of -20°C to 55°C. Note: Under Apple's public depth API, real-time depth readings are currently capped at 6 meters (20 feet) during the dive; upon surfacing, complete depth data (up to 40 meters) and water temperature profiles are recorded in Apple HealthKit and synced to ZDIVE.
- **Multi-Mode Tracking**: Dedicated Scuba Diving Mode (NDL, safety stops, ascent rate monitoring) and Snorkeling Mode (surface-to-depth cycles with automatic sub-dive detection).
- **Sensors Tracked**: Depth, water temperature, heart rate, blood oxygen (SpO2), compass heading, ambient pressure, and GPS breadcrumbs every 30 seconds.
- **Safety Monitoring**: Real-time ascent rate monitoring (with haptic and visual warnings), 6 configurable conservatism levels, 3-6m @ 3-7 min safety stops, tissue loading percentages, and automatic no-fly time calculations.
- **Dive Planning Suite**:
  - Multi-day trip planner with day-by-day scheduling and cumulative nitrogen loading estimation.
  - Gas planning suite: SAC rate calculation, Nitrox and Trimix planning, best mix recommendations.
  - Equipment packing list manager with 11 categories and 100+ pre-loaded items.
  - Buoyancy and weighting calculator with salinity adjustments.
  - Interactive Bühlmann ZH-L16C and PADI RDP decompression tables.
- **Breathing & Apnea Training**: 8 guided breathing exercises with visual timing rings: Box Breathing (4-4-4-4), 4-7-8 Relaxing Breath, Diaphragmatic Breathing, Square Freediving, CO2 Tolerance Tables, O2 Efficiency Tables, Wim Hof Method, and Tactical Breathing.
- **Cloud & Sync**: Automatic Apple CloudKit synchronization across iPhone and iPad, Apple HealthKit integration, and JSON import/export.
- **iOS Live Activities**: Real-time tissue loading and no-fly countdown on Dynamic Island and Lock Screen.

## Safety & Disclaimers

ZDIVE is an advanced dive planning, logging, and monitoring instrument. It is not a replacement for a certified primary dive computer, formal dive certification training (PADI, SSI, NAUI, etc.), or standard buddy procedures. Users must always dive with a dedicated, certified primary dive computer and follow the most conservative reading.

## Links & Resources

- [App Store Download](https://apps.apple.com/us/app/zdive/id6742788878)
- [Privacy Policy](https://zdive.app/privacy-policy)
- [Terms of Service](https://zdive.app/terms-of-service)
- [Full LLM Context (llms-full.txt)](https://zdive.app/llms-full.txt)