Comparison

AWU2UDDF vs ZDive

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

AWU2UDDF

Export underwater depth and temperature data from your Apple Watch to a standard UDDF XML file. This file can then be imported into popular diving log software for comprehensive record-keeping. It seamlessly integrates with the Health App and HealthKit.

Highlights
  • Export underwater depth and temperature data
  • Standard Universal Dive Data Format (UDDF) XML output
  • Import into Macdive or Subsurface
  • Integrates with Health App and HealthKit
Read full description

AWU2UDDF is used to export underwater depth and temperature data collected on your Apple Watch into a standard Universal Dive Data Format (UDDF) XML file. That file can then be imported into standard diving log software such as Macdive or Subsurface to complete your diving log. AWU2UDDF integrates with the Health App and the HealthKit framework to access the depth and temperature date stored by the phone.

About

ZDive

This app transforms your Apple Watch into a professional dive companion, offering real-time tracking, decompression algorithms, and advanced analytics. Plan your dives, optimize gas mixtures, and manage your diver profile with comprehensive tools for both recreational and technical diving.

Highlights
  • Real-time dive tracking
  • Decompression algorithms
  • Dive planning suite
  • Breathing trainer
  • Live Activities & Widgets
  • CloudKit backup and sync
Features
Read full description

ZDive transforms your Apple Watch into a smart dive companion with comprehensive iOS analytics. Whether you're snorkeling in tropical waters or logging recreational scuba dives, ZDive provides the tools you need for safe and memorable underwater adventures. APPLE WATCH — YOUR DIVE COMPANION Real-time dive tracking with automatic water submersion detection on Apple Watch Ultra (manual controls on other models) Rich sensor integration: depth, temperature, heart rate, compass, ambient pressure Scuba and snorkeling modes with Digital Crown navigation Industry-standard Bühlmann ZH-L16C decompression algorithm — the same model used by leading dive computers Real-time NDL calculations and safety stop monitoring Dive simulation mode: practice with realistic training scenarios Crash-safe recording: in-progress dives are checkpointed and automatically recovered GPS route tracking with breadcrumb trails Altitude diving support with automatic calibration Note: due to Apple's current API restrictions, live depth readings on Apple Watch are limited to about 6 meters. Deeper dives recorded with Apple's Depth app can be imported via HealthKit for full analysis. iOS APP — ADVANCED ANALYTICS & PLANNING Beautiful dive trends dashboard with period comparisons and personal records Interactive dive profile charts and sensor data visualization Diver profile with certifications and emergency contacts Import historical dives from Apple Health — duplicates are detected automatically Export dives in JSON and UDDF formats for other dive log software COMPREHENSIVE DIVE PLANNING SUITE Multi-Day Trip Planner with surface interval calculations Gas Planning Calculator: SAC rates, Nitrox optimizer, and a Trimix reference calculator Equipment Packing Lists with pre-built templates No-Decompression Planner with altitude compensation Interactive Decompression Tables: Bühlmann and PADI RDP PROFESSIONAL BREATHING TRAINER 10 breathing techniques: box breathing, 4-7-8, diaphragmatic Freediving-specific CO2 and O2 tolerance tables Wim Hof Method and tactical breathing patterns LIVE ACTIVITIES & WIDGETS Real-time tissue loading on Lock Screen and Dynamic Island No-fly time countdowns with maximum altitude restrictions Surface interval tracking between dives SAFETY & RELIABILITY 16-compartment tissue tracking with 6 conservatism levels Configurable safety stops (3–6 m depth, 3–7 minutes) Ascent rate monitoring with visual and haptic warnings Sensor data validation to filter spikes and false readings Automatic CloudKit backup and sync across devices Offline functionality with background synchronization SEAMLESS DATA MANAGEMENT Fast Watch-to-iPhone sync with optimized compression HealthKit integration for comprehensive health tracking Manual and automatic sync options with bulk import/export Try it instantly with a built-in demo dive — no gear required MULTI-LANGUAGE SUPPORT Available in English, Turkish, Chinese (Simplified), Russian, Spanish, Portuguese, Japanese, Arabic, French, Hindi, Bengali SUPPORTED DEVICES Apple Watch running watchOS 10.6 or later (Series 6 and later, SE, and Ultra) Apple Watch Ultra recommended: automatic submersion detection and enhanced diving sensors iPhone with iOS 17.6 or later, full iPad support for planning and analysis ZDive is free to use and supported by ads. Whether you're exploring coral reefs on a snorkel or logging recreational scuba dives, ZDive provides professional-grade planning and analysis tools in an intuitive interface. Note: ZDive is intended for recreational use as a dive companion and tracker, not as a certified dive computer. Always dive with certified diving equipment and follow proper safety protocols. Never rely solely on consumer devices for critical diving decisions. Join ZDive to enhance your underwater adventures. Dive deeper, plan smarter, and explore safely with ZDive.

Screenshots

AWU2UDDF3 screens
ZDive4 screens

Verdict

The call

The clearest difference is update cadence: ZDive at every 4 days against AWU2UDDF's every 14 months. ZDive also leads on device support (3 vs 1). On price, rating, review sentiment and ratings volume there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 5.0 for AWU2UDDF against 5.0 for ZDive. Both are backed by a comparable volume of ratings — 2 and 3 respectively. Written reviews split almost evenly too, at 100% and 100% positive.

UpkeepUpdate frequency

AWU2UDDF ships an update every 14 months, ZDive every 4 days. The most recent releases landed on November 3, 2026 and November 4, 2026 respectively.

Scorecard2 real differences · 8 level
AWU2UDDF versus ZDive: the parameters behind the verdict, then further details
ParameterAWU2UDDFZDive
PriceFreeFree
Rating5.0 (2 ratings)5.0 (3 ratings)
Positive reviews100.0% of reviews100.0% of reviews
Number of ratings23 — better
Update frequencyEvery 14 monthsEvery 4 days — better
AdsNoNo
In-app purchasesNoNo
MonetizationFreeFree
DevicesiPhoneiPhone, iPad, Apple Watch — better
Requires iOS16.0 — better17.6
Further details — not scored
Size1 MB17 MB
Age rating4+4+
DeveloperDouglas JunkinsZYORK SOFTWARE LLC

Customer experience

AWU2UDDF

All ratings2 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews2 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

ZDive

All ratings3 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews2 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

AWU2UDDF

No in-app purchases

None

ZDive

No in-app purchases

Questions

Is AWU2UDDF free?
AWU2UDDF is free to download, with no in-app purchases.
Is ZDive free?
ZDive is free to download, with no in-app purchases.
Which has better reviews, AWU2UDDF or ZDive?
AWU2UDDF and ZDive are both rated 5.0 out of 5 on the App Store, from 2 and 3 ratings respectively.
Do AWU2UDDF or ZDive have ads?
Neither AWU2UDDF nor ZDive shows ads.
Which is updated more often, AWU2UDDF or ZDive?
AWU2UDDF ships an update every 14 months, and ZDive every 4 days. Most recently, AWU2UDDF was updated on November 3, 2026 and ZDive on November 4, 2026.

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