Comparison

Abysner vs Halcyon Dive Systems

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

Head to head
About

Abysner

This app is an open-source dive planning tool designed for simplicity and ease of use. It supports various gas mixes and decompression models, allowing for accurate planning of technical and recreational dives. Its intuitive interface makes it suitable for use even in challenging conditions.

Highlights
  • Buhlmann ZHL-16 A, B, C models
  • Multi-gas support (Air, Nitrox, Trimix, etc.)
  • OTU and CNS tracking
  • Customizable environmental settings
  • Intuitive gas picker
  • Automatic contingency plans
  • Multi-level dive planning
Currently charting
Read full description

Abysner is an open-source, modern dive planning tool with a focus on simplicity and usability. Built to give something back to the diving community, its primary aim is not to be the most feature-rich, but to be quick, user-friendly, and straightforward. Whether you're planning a deep technical dive or just want to check your MOD, Abysner makes dive planning smooth, accurate, and fast—perfect for use even right beside the water. Supported Features: • Models: Supports Buhlmann ZHL-16 A, B, and C with gradient factors. • Multi-Gas Support: Plan dives with Air, Nitrox, Oxygen, Trimix, Helitrox, Heliox, and more. • Oxygen: Includes OTU and CNS tracking for safe dive planning. • Customizable Settings: • Set salinity and altitude according to the diving environment. • Adjust SAC rates, ascent/descent rates. • Fine-tune decompression stop intervals and last deco stop depth. • Control max PPO2 for both during deco stops and normal diving. • Gas Picker: An intuitive interface for selecting and managing gas mixes, with critical information at your fingertips. • Automatic Contingency Plans: Automatically adjusts for longer or deeper dives, with configurable extra time and depth. • Gas Planning: • Visual chart of gas requirements per mix. • Density and PPO2 info at maximum depths for each gas. • Multi-Level Dive Planning: Plan dives across different depths with ease. Please note: CCR planning is not available yet. More coming soon!

About

Halcyon Dive Systems

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
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Explore without limits: Your Ultimate Diving App Dive smarter and safer with the Halcyon App. Enjoy this powerful tool for logging, tracking, and sharing all your diving experiences while experiencing unprecedented integration with your Halcyon computer. With the Haclyon app you have full control over all computer settings, allowing the creation of profiles that include tailored settings and gases, pushed to the computer with the click of a button. You can also enjoy a full-featured "dry-diving" mode to explore all the unique features of our Symbios-connected products. From beginners to seasoned pros, the Halcyon App empowers you to explore the underwater world with confidence, share with our vibrant community, and track your diving progress. Key Features: Symbios Integration: Sync with Symbios-enabled devices, including the Handset, HUD, Rebreather and more. Manage your settings, create saved profiles with tailored settings and gases, track dive profiles, and access advanced metrics. Log Your Dives: Keep a detailed record of your dives. Monitor your progress over time and relive your diving adventures. Social Logbook: Share your dive stories, photos, and achievements with divers worldwide. Stay motivated and inspire others along the way. Diving Community: Connect with divers at any level. Share tips, discover new dive spots, and stay in the loop with the latest dive trends. Personalized Dive Tips: Get advice tailored to your diving experience with helpful tips and tricks, no matter your skill level. Halcyon Owner Benefits: Enjoy exclusive perks if you're a Halcyon owner—priority support, extended warranties, and special offers to get the most out of your gear. Why Choose Halcyon App? The Halcyon App isn’t just for logging and tracking—it’s your gateway to a richer diving experience. With cutting-edge technology, a thriving community, and personalized insights, the Halcyon App helps you dive smarter, stay connected, and explore like never before. Whether you're diving at a technical site or simply enjoying a recreational dive, the app ensures every dive is memorable, safe, and exciting. Stay Connected, Stay Inspired Join a passionate diving community where you can share experiences, connect with fellow divers, and keep up with the latest Halcyon innovations. The Future of Diving Is Here With Symbios Ecosystem integration, the Halcyon App lets you customize and track your gear, log dives, and connect with divers worldwide. Experience the underwater world with the latest tools, all from your phone. For Divers at Every Stage Whether you're just starting out or have hundreds of dives under your belt, the Halcyon App helps you track your dives, manage your gear, and stay in touch with the diving community. Download Halcyon App Today Join the next generation of divers—download Halcyon App and start exploring without limits.

Screenshots

Abysner4 screens
Halcyon Dive Systems4 screens

Verdict

The call

The clearest difference is price: Halcyon Dive Systems at Free against Abysner's $2.99. Halcyon Dive Systems also leads on update cadence (every 3 weeks vs every 2 months) and ratings volume (8 vs 2). Abysner's advantage is chart position (#184 vs unranked) and device support (3 vs 1). On rating, ads, in-app purchases 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

CostPrice · In-app purchases · Ads · Monetization

Halcyon Dive Systems is free to download; Abysner costs $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 5.0 for Abysner against 5.0 for Halcyon Dive Systems. Both are backed by a comparable volume of ratings — 2 and 8 respectively.

UpkeepUpdate frequency

Abysner ships an update every 2 months, Halcyon Dive Systems every 3 weeks. The most recent releases landed on October 27, 2026 and October 21, 2026 respectively.

Scorecard6 real differences · 5 level
Abysner versus Halcyon Dive Systems: the parameters behind the verdict, then further details
ParameterAbysnerHalcyon Dive Systems
Price$2.99Free — better
Rating5.0 (2 ratings)5.0 (8 ratings)
Positive reviews100.0% of reviews—
Number of ratings28 — better
Update frequencyEvery 2 monthsEvery 3 weeks — better
AdsNoNo
In-app purchasesNoNo
MonetizationPaidAd-supported — better
Best chart rank#184 — better—
DevicesiPhone, iPad, iPod — betteriPhone
Requires iOS15.3 — better16.0
Further details — not scored
Size42 MB162 MB
Age rating4+4+
DeveloperRoelof Rene SmitHalcyon Dive Systems

Customer experience

Abysner

All ratings2 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews2 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

Halcyon Dive Systems

All ratings8 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

Abysner

No in-app purchases

None

Halcyon Dive Systems

No in-app purchases

Questions

Is Abysner free?
Abysner costs $2.99, with no in-app purchases.
Is Halcyon Dive Systems free?
Halcyon Dive Systems is free to download, with no in-app purchases.
Which has better reviews, Abysner or Halcyon Dive Systems?
Abysner and Halcyon Dive Systems are both rated 5.0 out of 5 on the App Store, from 2 and 8 ratings respectively.
Do Abysner or Halcyon Dive Systems have ads?
Neither Abysner nor Halcyon Dive Systems shows ads.
Which is updated more often, Abysner or Halcyon Dive Systems?
Abysner ships an update every 2 months, and Halcyon Dive Systems every 3 weeks. Most recently, Abysner was updated on October 27, 2026 and Halcyon Dive Systems on October 21, 2026.

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