# Subsurface vs ATMOS

The clearest difference is review sentiment: Subsurface at 63% against ATMOS's 8%. Subsurface also leads on rating (4.5 vs 1.7). ATMOS's advantage is iOS requirement (14.0 vs 17). On price, ratings volume, update cadence and ads there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Subsurface holds the better App Store score, 4.5 against 1.7. Both are backed by a comparable volume of ratings — 48 and 23 respectively. Written reviews point the same way: 63% of Subsurface's written reviews are positive against 8% of ATMOS's.

Subsurface ships an update every 2 months, ATMOS every 5 weeks. The most recent releases landed on October 22, 2026 and October 15, 2026 respectively.

## The numbers

| Metric | Subsurface | ATMOS |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.5 (48 ratings)](https://appshunter.io/ios/app/subsurface-mobile/id1093217161/reviews)** | [1.7 (23 ratings)](https://appshunter.io/ios/app/atmos-diving-logbooks/id1448666557/reviews) |
| Number of ratings | **48** | 23 |
| Positive reviews | **63.3% of reviews** | 7.7% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 5 weeks** |
| Monetization | Free | Free |
| Size | 52 MB | 125 MB |
| Requires iOS | 17 | **14.0** |
| Devices | iPhone, iPad | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Dirk Hohndel](https://appshunter.io/developer/1093217160) | [ATMOS CO., LTD.](https://appshunter.io/developer/1448666556) |

## What reviewers say

### Subsurface

[App page](https://appshunter.io/ios/app/subsurface-mobile/id1093217161)

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

**In-app purchases:** none


### ATMOS

[App page](https://appshunter.io/ios/app/atmos-diving-logbooks/id1448666557)

This app wirelessly syncs dive logs from compatible dive computers. Users can view device information, edit dive log details, and export data in UDDF format. It also integrates with HealthKit to share dive-related health metrics.

**Highlights:** Wireless dive log sync, Device information check, Edit dive log details, Export to UDDF format, HealthKit integration

**In-app purchases:** none


## Frequently asked questions

### Is Subsurface free?

Subsurface is free to download, with no in-app purchases.

### Is ATMOS free?

ATMOS is free to download, with no in-app purchases.

### Which has better reviews, Subsurface or ATMOS?

Subsurface is rated higher. Subsurface averages 4.5 out of 5 from 48 ratings, while ATMOS averages 1.7 from 23 ratings.

### Do Subsurface or ATMOS have ads?

Neither Subsurface nor ATMOS shows ads.

### Which is updated more often, Subsurface or ATMOS?

Subsurface ships an update every 2 months, and ATMOS every 5 weeks. Most recently, Subsurface was updated on October 22, 2026 and ATMOS on October 15, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*