Logging offline — how it actually works

WatchKeeper is built for boats that spend days out of coverage. Short version: keep logging normally — the app queues everything and syncs itself when signal returns. Here's the precise version.

Works with no signal at all

On a phone, tablet, or laptop where the app has loaded before:

• Opening the app — the app shell is stored on the device.
• Reading your data — everything you've loaded stays readable for 30 days from the last time it synced, and that survives reloads, browser restarts, and device reboots. Open the app before you lose signal and any realistic passage is covered.
• Posting to the log — these forms write to a persistent on-device queue and survive a reload or restart:
  • Log Book entries (position, conditions, sails, engine)
  • Fish Log
  • VHF Radio Log
  • Incidents & Safety entries
  • Pilotage-plan "Skipper's Notes"
  • Watch shift start/end (the dashboard crew chips)
• Ticking Procedures checklists — ticks live on the device per vessel.

One naming note: the Log Book (where you post entries) and the Ship's Log (the read-only merged timeline of VHF, fish, service, and incident entries) are different pages. Everything above applies to the entry forms — the Ship's Log timeline simply re-displays what those forms recorded.

Each queued write carries its own idempotency ID, so a flaky satellite link that drops mid-sync cannot create duplicate entries — retrying is always safe.

Queues, but with a caveat

Actions outside the list above (say, editing a vessel profile while offline) also retry when the connection returns — but only if you keep the page open. They don't survive a reload while offline. When in doubt offshore, stick to the log forms above; that's what they're hardened for.

Needs a live connection

• First sign-in on a device — so sign in before you lose the dock Wi-Fi, and don't sign out mid-passage.
• Anything AI: shore-brief generation, Skipper AI, Provision meal plans.
• Weather, tides, AIS traffic, tracker position polls.
• Photo uploads, crew invite emails, billing, exports.

Shore briefs are generated and sent from the server on schedule, so your shore crew still gets them while you're offline — they'll just reflect the last data that synced.

Check the queue

Settings → Pending writes shows everything still waiting to sync, with attempt counts and any errors. The footer chip also shows a pending count whenever you're offline.

• Retry all — force a sync attempt (useful the moment signal returns).
• Remove — discard a queued write you no longer want.

A write that the server rejected (validation problem, plan limit) is not queued — it fails immediately with a message, so you can fix it while the details are fresh.

Before you head out — the 2-minute drill

1. Sign in on every device you'll log from.
2. Open the pages you'll want offshore (dashboard, logbook, procedures) once, so they're cached — the cache holds for 30 days.
3. Download the Offshore Manual and print the emergency card.