Halcyon Symbios Handset Dive Computer

The Halcyon Symbios Handset Dive Computer is the flagship handset computer within Halcyon’s growing Symbios ecosystem, designed for divers who want a compact, powerful and highly connected computer that can grow with their diving.

Suitable for advanced open-circuit diving, Trimix, fixed or integrated CCR, integrated sidemount, and gauge use, the Symbios combines a slim, ergonomic handset with wireless data integration, app-based setup, training simulation, and a bright, full-colour transflective display.

Halcyon Symbios 'Silver' Handset Computer At a Glance

• Symbios Wireless Ecosystem – The Symbios Handset can receive wireless data from multiple sources, including Tank Pods, rebreathers, DPVs, GPS buoys, dive lights, and more
• Gradient Factor Chart – Delivers real-time visualisation of compartment supersaturation and provides deeper insight into decompression obligations and decompression stress
• Patented Trim Indicator – Provides accurate, real-time feedback on diver trim and body position for optimal underwater efficiency and control (requires a Symbios Tank Pod)
• Training Mode – Allows divers to train decompression schedules, precise stop-depth control, and gas-switch procedures in a safe environment without actual decompression obligations
• Full Integration with the Symbios App (Android & iOS)
  • Dive computer setup (settings, gas tables, etc.)
  • Dive simulation
  • Dive data download and logbook
  • Integrated eCCR pre-dive checks
  • Social platform
• Buddy Screen – Displays pO₂ values and tank pressures from your buddy's Symbios eCCR. Particularly valuable for instructors, allowing them to monitor both their own and their students' eCCR data on a single device.
• Full-Color Transflective Screen – Perfectly readable in bright sunlight, even without backlight
• Ultra-Thin, Ergonomic Design
• Large, Easy-to-Read Display
• Pre-Programmed Gas Library
• Intuitive Two-Button Operation
• Extensive Customisation – Customisable fields, screens, and functions
• Supports Trimix OC, CCR, and Adjustable Gradient Factors

Halcyon Symbios – A Connected Dive Computer Ecosystem

Symbios is more than a single dive computer. It is a modular Halcyon system built around the Symbios Dive Computer, Symbios HUD, Symbios Tank Pod and Halcyon app. The HUD and handset can be used independently or combined to create a more complete connected diving system.

This means you can start with the handset alone, add wireless gas pressure and trim feedback with the Tank Pod, integrate the HUD for always-visible dive data, or expand further as the Symbios ecosystem develops.

Multi-Gas, Trimix, CCR and Sidemount Capability

The Symbios is a multi-gas dive computer that uses the ZHL16-C algorithm and features adjustable gradient factors. It accommodates up to five gases for open-circuit diving and supports fixed or integrated eCCR, integrated sidemount and gauge modes.

Depth-rated to 120 metres, the Symbios operates on a rechargeable Li-ion battery with up to 30 hours of runtime across five brightness levels. It displays key dive information including CNS, OTU accumulation, gradient factor data, CO2 information where available, and normal maximum average values for the dive.

Advanced Decompression Monitoring and Gradient Factor Visualisation

One of the standout features of the Symbios platform is its Gradient Factor chart, which provides divers with a clearer real-time view of decompression status and tissue loading.

Rather than simply showing stop information, the Symbios helps visualise which tissue compartments are influencing decompression obligation, giving experienced divers deeper insight into decompression stress and decision-making during the dive.

Wireless Integration, CCR Connectivity and Team Awareness

The Symbios Dive Computer can receive wireless data from multiple Symbios-compatible sources, supporting up to 9 transmitters. Depending on your configuration, this can include tank pressure, trim position, rebreather data, DPV information, positioning data and other connected system information as the ecosystem develops.

• From the Symbios Tank Pod: Gas pressure and real-time diver orientation / trim feedback.
  
• From compatible Symbios-connected CCR systems: PO2 values, battery state, CO2, scrubber temperature and other available rebreather data.
• From Symbios-enabled products: Future-ready integration for connected equipment such as DPVs, positioning systems and other supported devices.

The handset uses checksums to help isolate potentially corrupted data, supporting reliable wireless communication and reducing the risks associated with compromised signal transmission.

For team diving, the Symbios can also display selected buddy information where compatible devices are paired. This can include rebreather data or gas supply information, giving instructors, CCR divers and team divers a clearer view of critical values during the dive.

Real-Time Trim Feedback with the Symbios Tank Pod

When used with the optional Symbios Tank Pod, the Symbios Dive Computer can provide patented real-time trim feedback. This allows divers to monitor body position during the dive rather than relying only on instructor comments, video review or post-dive debriefing.

For divers focused on efficiency, stability, propulsion, and team positioning, this immediate feedback can be especially useful during training, skills refinement, and demanding technical dives.

High-Visibility Full-Colour Transflective Display

The Symbios features a 2.4-inch transflective full-colour display designed for excellent readability in real diving conditions. The screen reflects ambient light to improve clarity, remaining easy to read even in bright sunlight and helping reduce reliance on backlight power.

Large, clear data fields support quick recognition under task loading, while additional information is grouped into dedicated screens. Customisable fields and layouts allow the display to be tailored to the diver, the dive, and the required information.

Training, Simulation and Halcyon App Integration

The Halcyon app is an important part of the Symbios system, allowing divers to configure settings, manage gas libraries, adjust screen layouts, download dive data and access logbook features.

Its dry-dive and simulation capabilities allow divers to practise profiles, gas switches, decompression schedules, failures, and response scenarios before entering the water. This is particularly valuable for technical divers, CCR divers, instructors and anyone preparing for more complex dives.

The app also supports firmware updates and ongoing development of the Symbios platform, helping keep the computer current as new features and integrations become available.

Train dives before entering the water

• Simulate dives, gas switches, failures, and response scenarios through the mobile app.
• Practice open-circuit or rebreather procedures on land and refine your responses before entering the water.

Halcyon Symbios Dive Computer Features & Specifications

• Dive Modes: Open circuit, Trimix, fixed CCR, integrated CCR, integrated sidemount and gauge modes
• Algorithm: Bühlmann ZHL16-C with adjustable gradient factors and Gradient Factor visualisation
• Gas Support: Up to 5 OC/CC gases with pre-programmed gas library
• Wireless Integration: Supports up to 9 wireless connections, including Symbios Tank Pod and compatible connected devices
• Air Integration: Optional Symbios Tank Pod provides gas pressure monitoring and real-time trim feedback
• CCR Connectivity: Supports compatible Symbios-connected CCR systems with advanced monitoring and buddy screen functionality
• Display: 2.4-inch full-colour transflective screen, 320 x 240 resolution
• Controls: Two tactile-response buttons with customisable screen layouts
• Compass: 3-axis tilt-compensated digital compass with rose display
• Battery: Rechargeable Li-ion battery offering up to 30 hours runtime
• Dive Log: Stores up to 1000 hours of dive data at 5-second sampling
• Connectivity: Bluetooth connection with Halcyon app support, firmware updates, dive simulation and logbook management
• Alerts: Built-in vibration alerts
• Depth Rating: 120 metres
• Languages: English, German, Korean and Chinese
• Included: Blue bungee wrist strap and charging cable
• Dimensions: 94.4 x 63 x 19.8 mm

Why Choose DirDirect for Halcyon Symbios?

• Pioneering Halcyon in the UK: For nearly 25 years, we have been the UK's leading Halcyon dealer, with extensive experience in configuring Halcyon dive systems and technical equipment.
• Extensive Halcyon Inventory: Visit our dedicated technical diving and Halcyon showroom at our physical store to explore one of the UK's largest in-stock selections of world-leading diving products.
• Specialist Equipment Knowledge: Our commitment to Halcyon reflects a shared focus on robust equipment, careful configuration and practical diving experience across recreational, advanced and technical diving.