Every fill-to-full teaches it one exact gallons-per-hour sample. The more you run, the sharper the estimate — no setup, and you can override it anytime.
Tap START when the engine fires. Fuel drains by run time × your burn rate. The session survives a crash, force-quit, or reboot — it never loses a running timer.
A widget shows the fuel ring with a START/STOP button, and a Live Activity puts the live timer and fuel on the Lock Screen and Dynamic Island. The ring drains on its own — no background battery drain.
When the engine fires. The run timer is derived from a stored timestamp, so it survives a crash or reboot.
Fuel left, range, and time remaining update as you run — readable in the app, the widget, or on your wrist.
Tap “Filled up” when you refuel. Each fill-to-full sharpens your gallons-per-hour automatically.
While the timer runs, the phone records the route, distance, and speed by GPS and shows the track on a map. Location is on-device only, captured only during a run.
The same fuel ring, time remaining, and a START/STOP button on your wrist. Watch and phone keep their own logs and merge cleanly — no taps lost, even with the phone in a dry bag.
Every run, fill, and correction is an entry in an append-only log. Edit or void anything — voids are reversible, nothing is truly deleted — and export the whole history as JSON anytime.
It's an estimate, not a sensor. Fuel left = tank size − (run time × gallons-per-hour). Because an outboard's burn changes with throttle, the time-remaining is shown as a range, not a single number.
Treat it as a dependable backup gauge and planning tool — not a replacement for keeping an eye on your actual tank. Always carry an adequate fuel reserve and follow safe boating practices.
Get an approximate gauge that gets smarter every time you fill up — for outboards, portable tanks, generators, and RVs.