Subsurface vs Active Log
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Subsurface
This application allows divers to manage their dive logs on their mobile devices. It supports editing dive data and downloading new information from compatible dive computers. Optional cloud synchronization is available for seamless data transfer with desktop versions.
- Mobile dive log management
- Edit dive data
- Download from Bluetooth LE dive computers
- Optional cloud synchronization
- Open-source and free
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Subsurface-mobile is an iOS dive log application based on Subsurface, the best free open source dive log application available on Windows, Mac and Linux. Subsurface-mobile allows you to access your dive log on your tablet or phone, edit the data and even download new dive information from many Bluetooth LE enabled dive computers. Using a free Subsurface Cloud Storage account you can synchronize your dive data with the Subsurface desktop application (while significantly increasing the usefulness, the cloud account is not required to use Subsurface-mobile). To get support from the developers, please use the in-app menu entry "Ask for support" Please check out the Subsurface-mobile user manual: https://subsurface-divelog.org/documentation/subsurface-mobile-v3-user-manual (also available from within the app) Subsurface-mobile is free and open source. No ads, no commercial anything. And it comes with free cloud storage (if you decide to use that - it's optional). Your data aren't used for anything, nothing gets monetized.
Active Log
This app serves as a comprehensive dive logbook for scuba and freediving enthusiasts. It allows users to track progress, plan dives, import data from dive computers and existing files, and store important documents. It also includes safety calculators and works offline.
- Dive computer data import
- Log file import (SSRF, .FIT)
- Dive planning and profile tracking
- Document and certification storage
- Offline functionality
- Safety calculators (MOD, EAD, ppO2)
- Cloud sync across devices
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Active Log is an all-in-one app for scuba diving, technical diving, freediving, swimming and conditioning. Log and analyse your dives, import dives from supported dive computers, plan recreational and technical dives, train for freediving, create swimming workouts and improve your strength, endurance and conditioning. Whether you're a recreational diver, technical diver, freediver or swimmer, Active Log brings your activities, training and progress together in one place. DIVE LOGBOOK • Log recreational and technical scuba dives • Add dive details, locations, buddies, equipment, notes and photos • View your dive history and statistics • Track your progress and personal records • Store certifications, insurance, medical documents and assessments • Keep your diving information organised in one place DIVE COMPUTER & IMPORT Download dives directly from supported dive computers, including Shearwater, Suunto, Scubapro, Apeks and more. Import existing dive data from supported formats such as Subsurface/SSRF and FIT, or export and import dives in JSON format. Spend less time entering dive information manually and more time exploring your dives. DIVE PLANNER Plan your next dive before entering the water. Create recreational dive plans and review your dive profile, depth, time, gas requirements, decompression and expected run time. Keep your dive plans together with your dive logbook so you can plan, dive and review in one app. TECHDIVE Advanced planning and calculation tools for trained technical divers: • Decompression and multi-gas dive planning • Gas requirements and reserves • Gas Analyzer • Nitrox and Trimix blending • Recommended Gas Mix and Top-up Tank • MOD, EAD, END and PPO₂ calculations Active Log gives technical divers practical tools for preparing and analysing more complex dives. FREEDIVING Freediving is more than holding your breath. Train your breath, body and mind with: • CO₂ and O₂ tables • Custom apnea training • Dry training • Stretching and mobility • Mindset and mental preparation • Training history and progress tracking Build your freediving training around breathing, relaxation, physical preparation and mental performance. SWIMMING Train smarter in the pool or open water. • Create structured swimming workouts • Organise workouts into warm-up, main sets, drills, recovery and cooldown • Train freestyle, backstroke, breaststroke, butterfly and more • Track distance, sets, intensity and rest • Record your swims • Follow your swimming progress over time Whether you're swimming for fitness, technique or performance, Active Log helps you structure your training and keep improving. CONDITIONING Improve the fitness that supports your diving, freediving and swimming. Create conditioning workouts focused on: • Strength • Endurance • Mobility • General fitness Combine water training with physical conditioning to become stronger, fitter and better prepared for your activities. TRACK YOUR PROGRESS Active Log brings your diving, freediving, swimming and training history together so you can follow your performance, statistics, goals and personal progress over time. YOUR ACTIVITIES, ANYWHERE Active Log works offline, so important information remains available at the dive site, on the boat, at the pool or while travelling. Your data can also be securely stored in the cloud and accessed across multiple devices. DIVE. FREEDIVE. SWIM. TRAIN. Log your adventures. Plan what comes next. Train with purpose. Track your progress. Active Log — your water sports, one app. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
Screenshots
Verdict
The clearest difference is review sentiment: Active Log at 100% against Subsurface's 63%. Active Log also leads on rating (5.0 vs 4.5) and update cadence (every 3 days vs every 2 months). Subsurface's advantage is in-app purchases (none vs 4) and ratings volume (48 vs 1). 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. Active Log sells 4 in-app purchases, starting at $4.99 per year. Subsurface asks for nothing beyond the download.
Active Log holds the better App Store score, 5.0 against 4.5. That said, the two scores are not equally well evidenced: Subsurface has 48 ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 63% of Subsurface's written reviews are positive against 100% of Active Log's.
Subsurface ships an update every 2 months, Active Log every 3 days. The most recent releases landed on October 6, 2026 and October 10, 2026 respectively.
| Parameter | Subsurface | Active Log |
|---|---|---|
| Price | Free | Free |
| Rating | 4.5 (48 ratings) | 5.0 (1 ratings) — better |
| Positive reviews | 63.3% of reviews | 100.0% of reviews — better |
| Number of ratings | 48 — better | 1 |
| Update frequency | Every 2 months | Every 3 days — better |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Free — better | Free with in-app purchases |
| Devices | iPhone, iPad | iPhone, iPad, iPod — better |
| Requires iOS | 17 | 15.6 — better |
| Further details — not scored | ||
| Size | 52 MB | 75 MB |
| Age rating | 4+ | 4+ |
| Developer | Dirk Hohndel | Duong Do |
Customer experience
Subsurface
Active Log
In-app purchases
Subsurface
No in-app purchases
Active Log
- Freediving module (yearly)7 Days trial$4.991 Year
- TechDive module (yearly)7 Days trial$4.991 Year
- Swimming module (yearly)7 Days trial$4.991 Year
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- Diving module (yearly)7 Days trial$9.991 Year









