Devices that still work when the internet doesn't.

Watches & Wearables / dive computer

Shearwater Peregrine

D2 Cloud-Optional — Full function with the router off.

The unplug test

The Peregrine keeps diving exactly the same with no phone, no Wi-Fi, and no Shearwater account ever created. It turns itself on when submerged, runs its own decompression model, displays depth/time/NDL/deco stops on its own screen, and logs roughly 2000 dives in onboard memory -- none of that touches a network. Bluetooth only matters after you surface, and only if you want to pull dive logs onto a computer or phone or push a firmware update; both of those can be done through Shearwater's desktop or mobile app without ever signing into an online account. Skip Bluetooth entirely and the dive computer never notices.

Why this tier: Shearwater operates a real vendor cloud (Shearwater Cloud, with an optional online account that syncs dive logs across devices), so this is not the no-cloud-at-all case required for D1. But the decompression computer itself is fully standalone from the moment it is turned on underwater: it auto-powers on by pressure, calculates decompression on-device with the Buhlmann ZHL-16C model, and stores up to 2000 dives / 200 hours of detailed log in onboard memory with no phone, app, or account involved. Bluetooth Low Energy exists solely for two optional post-dive tasks -- downloading logs to Shearwater Cloud Desktop/Mobile and receiving firmware updates -- and the manual's own walkthrough of both procedures never shows an account-creation or sign-in step; the app itself supports an 'offline Shearwater account' mode in which, per Shearwater's own FAQ, 'none of your information will be saved to the cloud.' Setup and core function require no account and work fully unconnected -- the D2 row.

Specifications

Account requiredapp only
Works offlinefully
Lost when offlinesyncing dive logs to Shearwater's cloud and across multiple devices, which needs the optional 'online' Shearwater account, pulling dive logs onto a phone or computer for external analysis (the logs still exist onboard, up to ~2000 dives, but reading them off the watch needs the Shearwater Cloud app), receiving firmware updates, which are delivered only via Shearwater Cloud Desktop or Mobile over Bluetooth
Forced firmware updatesno
Radiosble
FCC ID2AA9B05
Local controlble
Phones homenone
Self-hostable none — no self-hosted replacement exists
No documented third-party or open-source tool reads Shearwater's BLE protocol for log download or firmware push; the Shearwater Cloud app is the only path, though it can be used without an online account. Does not affect core function, which never depends on the app.
Parts availableno
Availabilityin stock
Price band$550-600 (seen 2026-09-03)
Vendor risk 0 / 3

Where to buy

Open questions

Sources

Class A is primary (manual, FCC filing, teardown). Class B is corroborated community reporting. Class C is never sufficient alone.

History

Last verified 2026-09-03 — 3 days ago.