Comparison

Subsurface vs Deep Tools

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

Head to head
About

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.

Highlights
  • Mobile dive log management
  • Edit dive data
  • Download from Bluetooth LE dive computers
  • Optional cloud synchronization
  • Open-source and free
Read full description

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.

About

Deep Tools

This app is a comprehensive tool for divers, offering dive planning, logging, and gas blending. It supports recreational, technical, and rebreather diving with advanced decompression planning and dive computer integration. Plan complex dives, log your adventures, and mix gases with precision.

Highlights
  • Decompression dive planning (Bühlmann ZH-L16)
  • Dive log with Shearwater import
  • Nitrox and Trimix gas blending
  • Multiple dive calculators
  • Metric and imperial unit support
  • Multi-level and repetitive dive planning
Features
Read full description

The complete dive planner, dive log and dive calculator app for recreational, technical and rebreather divers. Plan decompression dives with Bühlmann ZH-L16 and gradient factors, import your dives from a Shearwater dive computer, blend nitrox and trimix, and get quick answers to the questions you ask before every dive. All in one app, for open circuit (OC) and CCR. Whether you are in dive training, planning complex deco dives, or logging your underwater adventures, Deep Tools gives you reliable results you can trust. DIVE CALCULATORS - Maximum Operating Depth (MOD) - Oxygen partial pressure (ppO₂) - Equivalent Air Depth (EAD) - Equivalent Narcotic Depth (END) - Equivalent Air Density Depth (EADD) - No Decompression Limit (NDL) - Best nitrox mix for depth - Best trimix mix for depth - Gas consumption (SAC / RMV) and gas density - Lift bag calculator DECO PLANNER * Plan complex dives with confidence on open circuit (OC) or rebreather (CCR): - Bühlmann ZH-L16B and ZH-L16C with gradient factors (GF) - Multi-level and repetitive dive planning - Lost gas plans and CCR bailout planning, with custom bailout points - Gas consumption, CNS and OTU for every dive - Dive profile, run time table, tissue pressure graph and slate view - Share dive plans as a file, text, slate or image DIVE LOG * - Import dives from Shearwater dive computers (Petrel, Perdix, NERD, Teric and more) - Full dive profile with ppO₂, CNS, TTS, SAC and gas density - Dive sites with name, coordinates, map and custom tags - Automatically merge dives with short surface intervals - Share dives with your buddies - Local backup and easy transfer to a new device GAS BLENDER * Mix accurate nitrox and trimix: - Partial pressure blending to the desired gas - Blending with a top-off gas - Continuous flow blending - Gas cost estimate MORE - Metric and imperial units - Altitude diving and water type (salt, fresh, EN13319) - Custom tank / cylinder database - Available in 11 languages * The deco planner, dive log and gas blender are included in Deep Tools Premium. Try them free during the free trial. Deep Tools is a planning aid. It does not replace proper dive training or certification. Special thanks to V. Paul Gordon, Serge Nelissen and Michael Heus for extensive testing and valuable contributions. Terms of Use: https://www.deepblue.si/privacy/terms-of-service.php Privacy Policy: https://www.deepblue.si/privacy/

Screenshots

Subsurface4 screens
Deep Tools4 screens

Verdict

The call

The clearest difference is in-app purchases: Subsurface at none against Deep Tools's 3. Subsurface also leads on review sentiment (63% vs 50%). On price, rating, ratings volume and update cadence 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. Deep Tools sells 3 in-app purchases, starting at $7.99 per month. Subsurface asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Deep Tools holds the better App Store score, 4.6 against 4.5. Both are backed by a comparable volume of ratings — 48 and 93 respectively. Written reviews complicate that: 63% of Subsurface's written reviews are positive against 50% of Deep Tools's, so the app with the better star average is not the one people write more warmly about.

UpkeepUpdate frequency

Both ship on a similar rhythm, roughly every 2 months. The most recent releases landed on November 2, 2026 and November 13, 2026 respectively.

Scorecard3 real differences · 7 level
Subsurface versus Deep Tools: the parameters behind the verdict, then further details
ParameterSubsurfaceDeep Tools
PriceFreeFree
Rating4.5 (48 ratings)4.6 (93 ratings) — better
Positive reviews63.3% of reviews — better50.0% of reviews
Number of ratings4893 — better
Update frequencyEvery 2 monthsEvery 2 months
AdsNoNo
In-app purchasesNo — betterYes
MonetizationFree — betterFreemium
DevicesiPhone, iPadiPhone, iPad
Requires iOS1717.0
Further details — not scored
Size52 MB13 MB
Age rating4+4+
DeveloperDirk HohndelDeep Blue d.o.o.

Customer experience

Subsurface

All ratings48 ratings
Positive89.6%
Neutral2.1%
Negative8.3%
Written reviews30 reviews
Positive63.3%
Neutral6.7%
Negative30.0%

Deep Tools

All ratings93 ratings
Positive91.4%
Neutral2.2%
Negative6.5%
Written reviews6 reviews
Positive50.0%
Neutral16.7%
Negative33.3%

In-app purchases

None

Subsurface

No in-app purchases

3 purchases

Deep Tools

Subscriptions2
  • Subscription Monthly$7.991 Month
  • Subscription Yearly3 Days trial$22.991 Year
One-time1
  • Lifetime Subscription$49.99

Questions

Is Subsurface free?
Subsurface is free to download, with no in-app purchases.
Is Deep Tools free?
Deep Tools is free to download, with in-app purchases available.
Which has better reviews, Subsurface or Deep Tools?
Deep Tools is rated higher. Subsurface averages 4.5 out of 5 from 48 ratings, while Deep Tools averages 4.6 from 93 ratings.
Do Subsurface or Deep Tools have ads?
Neither Subsurface nor Deep Tools shows ads.
Which is updated more often, Subsurface or Deep Tools?
Subsurface ships an update every 2 months, and Deep Tools every 2 months. Most recently, Subsurface was updated on November 2, 2026 and Deep Tools on November 13, 2026.

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