Subsurface vs Tech Dive
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.
Tech Dive
This app helps plan scuba dives with various calculators for gas, depth, and air consumption. It supports metric and imperial units and offers advanced features through an in-app purchase.
- Dive planning calculators
- Gas and air consumption calculations
- Metric and imperial unit support
- Depth and EAD calculations
- Enriched Air-Nitrox mix calculation
- Unit conversion tools
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Diving should be safe and fun. We develop Tech Dive as a simple tool to plan and calculate your next underwater adventure. Tech Dive is an advanced scuba dive calculator and supports metric and imperial units. This app continues to grow as a one-stop technical diver tool. A technical decompression (DECO) planner will be incorporated with the future PRO version. DIVE CALCULATORS Tool for accurate dive planning, education, and training. ▸ Surface Air Consumption - SAC ▸ Respiratory Minute Volume - RMV ▸ Maximum Bottom Time ▸ Gas Required ▸ Maximum Operating Depth - MOD ▸ Equivalent Air Depth - EAD ▸ Best Enriched Air-Nitrox (EAN) Mix ▸ Equivalent Narcotic Depth - END (Plus only) ▸ Trimix Gas Planner (Plus Only) ▸ Cylinder Fill (Plus only) ▸ Cylinder Top-Up (Plus only) CONVERSION TOOLS ▸ Metric / Imperial Units ▸ Absolute Depth (Atmospheric Depth) ▸ Cylinder Volume / Pressure ▸ Partial Pressure PLUS FEATURES (IN-APP PURCHASE) Tech Dive Plus includes all basic features plus: ▸ Equivalent Narcotic Depth - END Calculator ▸ Trimix Gas Planner ▸ Cylinder Fill calculations (Air, Nitrox, Trimix) ▸ Cylinder Top-Up calculations ▸ Export/share all calculation results as PDF SUBSCRIPTION TERMS Tech Dive is free to download and the basic features free to use. A paid upgrade to Plus or PRO versions provide access to premium features and additional tools. We may offer trial subscriptions that give limited time access to paid features and premium content for the duration of the trial period. Trial subscriptions automatically expire and the app will revert back to the basic version thereafter. No data is lost but access and use of premium features will no longer be available.
Screenshots
Verdict
The clearest difference is review sentiment: Tech Dive at 100% against Subsurface's 63%. Tech Dive also leads on rating (5.0 vs 4.5) and update cadence (every 2 weeks vs every 2 months). Subsurface's advantage is in-app purchases (none vs 2) and ratings volume (48 vs 2). On price, ads, device support and iOS requirement 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. Tech Dive sells 2 in-app purchases, starting at $0.99 per month. Subsurface asks for nothing beyond the download.
Tech Dive 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 2, 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 Tech Dive's.
Subsurface ships an update every 2 months, Tech Dive every 2 weeks. The most recent releases landed on September 18, 2026 and August 8, 2026 respectively.
| Parameter | Subsurface | Tech Dive |
|---|---|---|
| Price | Free | Free |
| Rating | 4.5 (48 ratings) | 5.0 (2 ratings) — better |
| Positive reviews | 63.3% of reviews | 100.0% of reviews — better |
| Number of ratings | 48 — better | 2 |
| Update frequency | Every 2 months | Every 2 weeks — better |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Free — better | Free with in-app purchases |
| Devices | iPhone, iPad | iPhone, iPad |
| Requires iOS | 17 | 17.0 |
| Further details — not scored | ||
| Size | 52 MB | 16 MB |
| Age rating | 4+ | 4+ |
| Developer | Dirk Hohndel | Skytip LLC |
Customer experience
Subsurface
Tech Dive
In-app purchases
Subsurface
No in-app purchases
Tech Dive
- Plus Monthly$0.991 Month
- Plus Annual$7.991 Year








