From the subsurface website.....
How do I download dives from my Bluetooth LowEnergy, BLE, Bluetooth Smart dive computer (e.g., Shearwater Perdix AI, Shearwater Perdix (latest models), Suunto EON Steel)?
At this point (September 2017, Subsurface 4.6.4) the release versions of Subsurface and Subsurface-mobile don’t support connecting to dive computers over BLE. We are actively working on this support and have test binaries for Mac (Subsurface) and Android (Subsurface-mobile) that support a hand full of BLE based dive computers. Windows support is a lot further away. While we have plans for a 4.7 version of Subsurface which includes this support, we have no expected release time frame, yet.
Edit- you have to download dives to a computer first and then they can be transferred to the app over the cloud. Stuff that, I'll stick with DiveLog.
Edit2- it just decided to connect lol after all that, I'm not a fan.