# Halcyon Dive Systems vs Time to Surface

The clearest difference is update cadence: Time to Surface at every 2 days against Halcyon Dive Systems's every 3 weeks. Time to Surface also leads on monetization model (free vs ad-supported). Halcyon Dive Systems's advantage is ratings volume (8 vs 1). On price, rating, ads and in-app purchases there is nothing between them.

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

On the App Store both sit at effectively the same score — 5.0 for Halcyon Dive Systems against 5.0 for Time to Surface. That said, the two scores are not equally well evidenced: Halcyon Dive Systems has 8 ratings behind it against 1, so its average is the more settled of the two.

Halcyon Dive Systems ships an update every 3 weeks, Time to Surface every 2 days. The most recent releases landed on October 21, 2026 and October 7, 2026 respectively.

## The numbers

| Metric | Halcyon Dive Systems | Time to Surface |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [5.0 (8 ratings)](https://appshunter.io/ios/app/halcyon-dive-systems-diving/id6738069654/reviews) | [5.0 (1 ratings)](https://appshunter.io/ios/app/time-to-surface-deco-planner/id6803187271/reviews) |
| Number of ratings | **8** | 1 |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 3 weeks | **Every 2 days** |
| Monetization | Ad-supported | **Free** |
| Size | 162 MB | 4 MB |
| Requires iOS | **16.0** | 17.0 |
| Devices | iPhone | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Halcyon Dive Systems](https://appshunter.io/developer/1779189368) | [RUSTAM ISMAILOV](https://appshunter.io/developer/6799582362) |

## What reviewers say

### Halcyon Dive Systems

[App page](https://appshunter.io/ios/app/halcyon-dive-systems-diving/id6738069654)

This app helps divers log, track, and share their underwater experiences. It offers integration with dive computers, personalized settings, and a community forum for connecting with other divers.

**Highlights:** Symbios integration for dive computer settings, Detailed dive logging and progress tracking, Social logbook for sharing dive stories, Connect with a global diving community, Personalized dive tips and advice, Exclusive benefits for Halcyon owners

**Features:** macOS Compatibility, Apple Wallet, Vision Pro support

**In-app purchases:** none


### Time to Surface

[App page](https://appshunter.io/ios/app/time-to-surface-deco-planner/id6803187271)

This technical dive planner calculates staged decompression for dives up to 56 meters. It supports multiple bottom gases and one deco bottle, offering detailed gas planning, runtime tracking, and contingency solutions. The app also accounts for repetitive dives and provides a printable wetnote layout.

**Highlights:** Staged decompression planning (15-56m), Support for six bottom gases and one deco gas, Twin cylinder configuration, Bühlmann ZH-L16C model with adjustable gradient factors, Adjustable ppO2 and descent rates, Repetitive dive planning, Contingency scenario calculations

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is Halcyon Dive Systems free?

Halcyon Dive Systems is free to download, with no in-app purchases.

### Is Time to Surface free?

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

### Which has better reviews, Halcyon Dive Systems or Time to Surface?

Halcyon Dive Systems and Time to Surface are both rated 5.0 out of 5 on the App Store, from 8 and 1 ratings respectively.

### Do Halcyon Dive Systems or Time to Surface have ads?

Neither Halcyon Dive Systems nor Time to Surface shows ads.

### Which is updated more often, Halcyon Dive Systems or Time to Surface?

Halcyon Dive Systems ships an update every 3 weeks, and Time to Surface every 2 days. Most recently, Halcyon Dive Systems was updated on October 21, 2026 and Time to Surface on October 7, 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.*