DiveCore vs U
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
DiveCore
This app transforms your Apple Watch Ultra into a professional dive computer. It uses on-device AI to analyze your dives, providing insights into safety, efficiency, and consistency. Features include real-time decompression modeling, estimated dive routes, and a no-fly timer.
- Bühlmann ZHL-16C decompression model
- Real-time NDL + decompression ceiling display
- Estimated dive route visualization
- No-fly timer with Live Activity
- On-device AI dive scoring
- Dive log with iCloud sync
- Underwater color correction
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DiveCore — A real dive computer for Apple Watch Ultra DiveCore harnesses your Apple Watch Ultra's water-resistant depth sensor, compass, and accelerometer to give divers everything they need right on their wrist. It pairs with the iPhone companion app in real time and uses on-device AI to help you improve your dive patterns. [ Core Features ] Dive Computer (Apple Watch Ultra) - Bühlmann ZHL-16C with adjustable Gradient Factors - Real-time 16-tissue compartment decompression model - No-decompression limit (NDL) and decompression ceiling - Automatic safety stop countdown (3 min @ 3-6 m) - Ascent rate alarm + haptic warnings - PPO2 oxygen limit alarm - Auto water lock - HealthKit workout session integration - 30Hz smooth digital compass Freediving Mode - Depth disciplines (CWT / CWTB / FIM), static apnea (STA), dynamic apnea (DYN / DNF) - Automatic dive detection for depth, manual timer with lap entry for pool disciplines - Dive count, max depth, surface interval, heart rate, and a per-session log - A session spans many dives: surfacing starts the rest timer, and you end the session yourself - Freedive mode runs no decompression model and no gas or NDL alarms - It cannot detect shallow-water blackout. Never freedive alone, and always dive with direct, trained supervision Estimated Dive Route - Surface GPS captured at entry and exit - Underwater path estimated from compass + gyro + accelerometer + depth changes - End-of-dive drift correction using exit GPS - 3D visualization on iPhone (depth profile walls, drag-to-rotate, pinch-to-zoom) - Insights: average speed, activity level, exploration pattern, current drift estimation This is not real underwater GPS tracking. It is a sensor-fusion estimate based on the diver's magnetic heading and motion, with both endpoints corrected by surface GPS fixes. No-Fly Timer (Live Activity) - DAN/UHMS guideline tiers (12h single no-deco / 18h repetitive or multi-day / 24h decompression), never shortened by a later dive - Lock-screen + Dynamic Island countdown AI Analysis (XAI — Explainable) - 100% on-device, no external API calls - Dive score (0-100) with breakdown (Safety, Efficiency, Consistency, Condition, Depth Management) - Real-time Risk Index and automatic stress zone detection - Personal baseline learning Dive Log + Share - iCloud automatic sync across devices - Auto-recorded: water temp, gas mix, SAC, tank pressure, algorithm, no-fly time - Infographic share card, 1080x1350 - Entry/exit coordinates open in Apple Maps DiveCore Studio (Photo Editor) - Underwater color correction, depth-based red channel restoration, AI dehaze - Dive log watermark Watch Display Customization - Technical bottom bar: choose what it shows, including heading (HDG) - Minimal: 3 configurable bottom-card slots and MAX ring field selection iPhone Companion - Detailed dive log with depth profile chart - PADI RDP dive planner, AI report, dive site location, statistics, iCloud backup [ Required Hardware ] - Apple Watch Ultra (1st generation or later) - iPhone with iOS 18+ - iCloud account + Apple Sign-In [ Accessibility ] - VoiceOver support and Dynamic Type - 14 languages [ Subscription Terms ] - DiveCore Pro (choose one; all unlock the full feature set): - Yearly: $29.99/year (KRW 44,000) - includes a 7-day free trial for new subscribers - Monthly: $4.99/month (KRW 7,700) - no free trial - 1-Day Pass: $2.99 (KRW 3,300) - 24-hour access, non-renewing (does not auto-renew) - Local currency may apply; prices are set per storefront. - Payment is charged to your Apple ID account at confirmation of purchase - Yearly and Monthly auto-renew unless cancelled at least 24 hours before the end of the current period - If not cancelled at least 24 hours before the trial ends, you will be charged automatically - Manage or cancel your subscription anytime in your device's App Store account settings - Terms of Use (EULA): https://furyus.dev/terms
U
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U-Dive is an Apple Watch companion for freediving and snorkel training. Put on your watch, get in the water — it handles the rest. ◆ On Apple Watch • Automatic submersion & dive detection — recording starts hands-free • Live depth and water temperature (depth display capped at 6 m in this release) • Continuous heart-rate recording during dives — watch your mammalian dive reflex • Surface-interval timer with haptic surfacing alert • Custom depth alerts with haptic feedback • Personal max-depth record notifications • GPS entry/exit coordinates for every dive • Action Button support: start a session, flag a dive, review history • Auto Water Lock — long-press the crown to end & save • Built-in dive simulator to try the full flow on dry land ◆ On iPhone • Dive-spot map with favorites, notes and custom icons • Import Google My Maps layers (KML) • Paste a Google Maps share link to create a spot • Full dive log: depth profile, heart rate, duration and coordinates • Share and export your dives ◆ About Lite This release uses Apple's shallow-depth API: depth display is capped at 6 m, while time, heart rate and GPS keep recording beyond it. A full-depth version is in progress. ◆ Requirements • Depth and auto dive detection require an Apple Watch Ultra (depth gauge) • Other Apple Watch models work in manual mode (HR, GPS, timers, log) • The iPhone app manages spots and logs; the watch app runs independently ◆ Safety This app is not a dive computer and must not be used for dive safety or decompression decisions. Not for scuba diving. Freediving is dangerous — never dive alone, follow one-up-one-down, and get certified training.
Screenshots
Verdict
The clearest difference is in-app purchases: U at none against DiveCore's 3. DiveCore's advantage is update cadence (every 4 days vs every 2 weeks) and iOS requirement (18.0 vs 26.4). On price, ads and device support 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
Both are free to download. DiveCore sells 3 in-app purchases, starting at $4.99 per month. U asks for nothing beyond the download.
DiveCore ships an update every 4 days, U every 2 weeks. The most recent releases landed on October 10, 2026 and October 16, 2026 respectively.
| Parameter | DiveCore | U |
|---|---|---|
| Price | Free | Free |
| Positive reviews | 100.0% of reviews | — |
| Update frequency | Every 4 days — better | Every 2 weeks |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Monetization | Freemium | — |
| Devices | iPhone, Apple Watch | iPhone, Apple Watch |
| Requires iOS | 18.0 — better | 26.4 |
| Further details — not scored | ||
| Size | 23 MB | 10 MB |
| Age rating | 12+ | 4+ |
| Developer | juseong kim | Yao YungTai |
In-app purchases
DiveCore
- DiveCore Pro (Monthly)$4.991 Month
- DiveCore Pro (Yearly)7 Days trial$29.991 Year
- DiveCore Pro 1-Day Pass$2.99
U
No in-app purchases









