# Trimix Tools vs Subsurface

The clearest difference is price: Subsurface at Free against Trimix Tools's $6.99. Subsurface also leads on ratings volume (48 vs 5). Trimix Tools's advantage is rating (5.0 vs 4.5) and review sentiment (100% vs 63%). On update cadence, ads and in-app purchases there is nothing between them.

Subsurface is free to download; Trimix Tools costs $6.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Trimix Tools 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 5, so its average is the more settled of the two. Written reviews point the same way: 100% of Trimix Tools's written reviews are positive against 63% of Subsurface's.

Trimix Tools ships an update every 4 months, Subsurface every 2 months. The most recent releases landed on November 6, 2026 and November 2, 2026 respectively.

## The numbers

| Metric | Trimix Tools | Subsurface |
| --- | --- | --- |
| Price | $6.99 | **Free** |
| Rating | **[5.0 (5 ratings)](https://appshunter.io/ios/app/trimix-tools/id289220808/reviews)** | [4.5 (48 ratings)](https://appshunter.io/ios/app/subsurface-mobile/id1093217161/reviews) |
| Number of ratings | 5 | **48** |
| Positive reviews | **100.0% of reviews** | 63.3% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 4 months | **Every 2 months** |
| Monetization | Paid | **Free** |
| Size | 6 MB | 52 MB |
| Requires iOS | **15.6** | 17 |
| Devices | **iPhone, iPad, iPod, Mac** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Greg Mclaughlin](https://appshunter.io/developer/284919983) | [Dirk Hohndel](https://appshunter.io/developer/1093217160) |

## What reviewers say

### Trimix Tools

[App page](https://appshunter.io/ios/app/trimix-tools/id289220808)

This app provides essential tools for divers to plan and blend Trimix gases. It calculates optimal mixes based on depth, oxygen partial pressure, and equivalent narcotic depth, and supports various cylinder filling scenarios. Calculations are available offline and can be customized with saved settings.

**Highlights:** Trimix blending and planning, Depth and partial pressure calculations, Equivalent Narcotic Depth (END) calculation, Saltwater and freshwater support, Cylinder filling and bleed down calculations, Metric and Imperial system support, Offline functionality, Saved settings and custom mixes

**Features:** Vision Pro support

**In-app purchases:** none


### 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


## Frequently asked questions

### Is Trimix Tools free?

Trimix Tools costs $6.99, with no in-app purchases.

### Is Subsurface free?

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

### Which has better reviews, Trimix Tools or Subsurface?

Trimix Tools is rated higher. Trimix Tools averages 5.0 out of 5 from 5 ratings, while Subsurface averages 4.5 from 48 ratings.

### Do Trimix Tools or Subsurface have ads?

Neither Trimix Tools nor Subsurface shows ads.

### Which is updated more often, Trimix Tools or Subsurface?

Trimix Tools ships an update every 4 months, and Subsurface every 2 months. Most recently, Trimix Tools was updated on November 6, 2026 and Subsurface on November 2, 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.*