Submersion Dive Log vs Reef

Submersion is a comprehensive, open-source dive log for recreational and technical divers. Track dives, manage gear, analyze trends, and export to open formats. No subscriptions, no proprietary lock-in, no cost. COMPLETE DIVE LOGGING • Log unlimited dives with depth, duration, temperature, and conditions • Track entry/exit times with automatic surface interval calculation • Rate dives, add notes, and organize with custom tags • Record visibility, current, waves, weather, and water type • Support for 20+ dive types including night, wreck, cave, and technical DIVE COMPUTER INTEGRATION • Connect via Bluetooth or USB to well known dive computer models • Import dive profiles with one tap—no cables to your computer needed • Smart duplicate detection prevents importing the same dive twice • Supported brands: Shearwater, Suunto, Mares, Aqualung, Garmin, Oceanic, and many more ADVANCED PROFILE ANALYSIS • Interactive depth/temperature charts with zoom and pan • Bühlmann ZH-L16C decompression algorithm with gradient factors • Real-time NDL, ceiling, and tissue loading visualization • Ascent rate monitoring with color-coded warnings • O₂ toxicity tracking (CNS%, OTU, ppO₂) for nitrox and trimix divers • SAC/RMV calculation and trend analysis TECHNICAL DIVING READY • Multi-tank support with unlimited cylinders per dive • Full gas mix tracking: Air, Nitrox, Trimix, and pure O₂ • Gas switch markers on dive profiles • MOD, END, and EAD calculations built-in • Tank presets for quick logging (AL80, HP100, Steel 12L, and more) GEAR & EQUIPMENT MANAGEMENT • Track all your gear: regulators, BCDs, computers, suits, and more • Service history with reminders when maintenance is due • Create equipment sets for different diving configurations • Weight calculator based on exposure suit and conditions DIVE SITES & MAPS • Build your personal dive site database with GPS coordinates • Interactive map with clustered markers showing all your sites • Capture location from your phone or pick from the map • Automatic reverse geocoding fills in country and region • Track site details: depth range, difficulty, hazards, and access notes MARINE LIFE TRACKING • Log species sightings with counts on each dive • Pre-loaded database with common species • Build your personal life list over time BUDDIES & CERTIFICATIONS • Manage your dive buddy list with certification levels • Track your own certifications with expiry reminders • Associate buddies and instructors with each dive • Log dive centers and boat names STATISTICS & INSIGHTS • Total dives, bottom time, and depth records • SAC trends over months and years • Temperature preferences by season • Dive frequency charts and gas mix distribution • Deepest, longest, coldest, and warmest dive records CLOUD SYNC & BACKUP • Sync across all your devices via iCloud or Google Drive • Local-first design works completely offline • Export to UDDF, CSV, or PDF • Import from other dive log apps PRIVACY FOCUSED • No account required—start logging immediately • Your data stays on your device (unless you enable cloud sync) • No ads, no tracking, no subscriptions • Open source: inspect the code yourself on GitHub Whether you're a new diver logging your first open water dives or a technical diver tracking complex trimix profiles, Submersion adapts to your needs. Join the growing group of divers who trust Submersion to preserve their dive information. Questions or feedback? Visit our GitHub repository.

Every dive deserves a beautiful record. Reef is the simplest, cleanest scuba diving logbook for iOS — built for recreational divers who want their dive history to look as good as it felt underwater. LOG YOUR DIVES Depth, duration, water temp, visibility, air consumption, tank pressure, dive site and notes. Tap in at the surface while it's fresh. Works fully offline on liveaboards and remote reefs. TRACK YOUR STATS Total dives, deepest dive, longest bottom time and top dive sites by count. Watch your logbook grow with every trip. ATTACH PHOTOS Turn each dive entry into a visual story. Add photos straight from your camera roll to any log entry. DIVE BUDDY Log who you dived with. Build your buddy history across every trip and location. DIVE SITES & MAP Pin exactly where you dived on a map. Open your dive map anytime to see every logged site across the world — your personal underwater atlas. GEAR LOCKER Store all your dive equipment in one place. Track service intervals by dive count and time — Reef tells you when your BCD, regulator, wetsuit or mask is due for a service before it becomes a problem. CERTIFICATIONS Store all your dive certifications in one place. See at a glance which are valid, expiring soon or expired — always ready to show at the dive centre. No social network. No subscription required to log dives. Just a beautiful, private logbook — always in your pocket. Compatible with PADI, SSI, NAUI, CMAS and all major certification agencies. Terms of Use (EULA): https://reeflogbook.app/terms