Halcyon

Halcyon Symbios Handset

A modular technical handset with a sunlight-readable transflective display and CCR support.

Open BLE sync (libdivecomputer)

Syncs wirelessly with third-party apps (Subsurface, Currents, etc.), not just the manufacturer app.

Halcyon Symbios Handset
$900
Released2025
Max depth rating120m
AlgorithmZHL-16C with adjustable gradient factors
Air integrationwireless
Wireless—
DisplayFull-color transflective display, five brightness levels
Batteryrechargeable
Digital compass—
Gas typesair, nitrox, trimix
Gas switches5
CCR capableYes

"Gas switches" is how many different mixes this computer can be programmed to switch between mid-dive, mostly relevant for technical/staged-decompression diving. It doesn't tell you which gas types (air, nitrox, trimix) are supported. See Gas types and the product description above for that.

Pros
  • Transflective display stays readable in bright sun without a constantly-on backlight, saving battery
  • Up to 30 hours of runtime per charge
  • Displays CCR sensor data, buddy information, DPV and light status when paired with other Symbios devices
Cons
  • Price varies by finish/tier ($900-$1,195 depending on color and configuration)
  • Requires a Halcyon Tank POD for tank pressure display
  • Ecosystem-dependent, full feature set needs other Symbios-paired hardware

The Symbios Handset is the wrist-style computer in Halcyon’s modular Symbios system, built for technical and CCR divers who want a sunlight-readable display that can also surface tank pressure, buddy status, and CCR sensor data when paired with the rest of the ecosystem.