Anchor Alarm
Anchor Alarm in plain language
Anchor Alarm watches whether the boat stays inside a defined area around the anchor. The monitoring device continuously reads its position, measures the distance from the anchor and sounds an alarm after a confirmed zone exit or loss of position.
Set-up step by step
Select the anchor icon, then Settings. Check that the current position and its quality are visible.
On Android, use the phone location or NMEA/Wi‑Fi. On a computer, connect an NMEA/USB GPS.
Use the current location, pick a point on the map, enter distance and bearing from the boat, or choose “Resume alarm” to return to the previous anchor.
Choose a circular or directional zone and match the distances to the location, weather and chain length.
Review the summary. The button becomes available after stable positions are received and the anchor and zone are valid.
Four ways to set the anchor
Choose the method that matches the situation on board. Once set, the anchor stays at a fixed point on the map — it does not move with the boat.
| Method | How it works | When to use it |
|---|---|---|
| Current location | Sets the anchor at the boat’s current GPS position. | When the boat is over the place where the anchor was dropped. |
| Pick on map | Lets you select the anchor position directly on the map. | When you know the anchor location and want to place it manually. |
| Distance and bearing | Calculates the anchor position from the boat’s current position using the distance and bearing you provide. | When the boat has moved away from the anchor. For example, 10 m and 90° places the anchor 10 m east of the boat. |
| Resume alarm | Restores the last saved anchor, its zone and settings without setting the position again. | When the alarm was stopped but you are still using the same anchor. |
In “Distance and bearing”, Auto is on by default. The bearing updates from the phone compass and the field is read-only. Turn Auto off to enter a bearing manually from 0–359°. “Set anchor” uses the value shown in the field: either the compass reading or your manual bearing.
Hold the phone flat and away from magnetic interference. If the device cannot provide a current compass reading, turn Auto off and enter the bearing manually. Auto sets the direction only — it does not replace the GPS position or arm the alarm.
Resume alarm — return to the previous anchor
The boat may move after the alarm is stopped, while the anchor stays in the same place. “Resume alarm” lets you return to the last anchor saved when the alarm was previously armed on this device. The option requires a saved anchor and a current GPS position of sufficient quality.
- In “Set anchor”, choose “Resume alarm”. The saved details expand in the same panel without opening another window.
- Check the boat’s current position and the previous anchor position. Distance and bearing to the saved anchor update live, while its coordinates stay fixed.
- Choose “Set again” to restore the anchor on the map, the previous zone type — circular or directional — and its settings. You can adjust the maximum distance and other parameters before or after restoring; your new limit is not overwritten by the old one.
- Check the zone and choose “Arm alarm”. “Set again” alone does not start monitoring. After changing the limit, you do not need to restore the anchor again — simply arm the alarm once GPS and the other requirements are met.
A red value in “Resume alarm” means the boat is outside the previous zone. You can increase or reduce the limit, but until the alarm is armed again the colour still refers to the previously saved zone. For example, with a previous limit of 20 m, a distance of 22 m stays red even after entering a new limit of 25 m. The new settings are saved after the alarm is successfully armed.
What the statuses mean
| Status | Meaning | What to do |
|---|---|---|
| Inactive | The alarm is not monitoring the boat's movement. | Set the anchor and zone or use “Resume alarm”, then select “Arm alarm”. |
| Safe | The boat is inside the allowed zone and the position is current. | No action is needed; monitoring continues. |
| Alarm | A zone exit has been confirmed. | Check the boat and conditions. Muting for one minute does not stop monitoring. |
| No position | The selected source is not providing a current, valid position. | Check GPS, cable, Wi‑Fi, NMEA and permissions. The alarm does not switch sources automatically. |
Position sources
The source selected for Anchor Alarm is separate from Route and Planner. Once the alarm is armed, the source is locked so an accidental change cannot interrupt monitoring.
| Device | Available source | Important while in use |
|---|---|---|
| Android | Automatic phone location or external NMEA/Wi‑Fi (TCP/UDP). | A native background service runs after arming. NMEA does not automatically fall back to the phone GPS. |
| Computer | An external GPS sending NMEA over USB. | The browser must support Web Serial. Keep BayPilot open and prevent the computer from sleeping. |
| Mobile web | The phone location shared with the browser. | Keep the page open and the screen awake. A browser cannot guarantee continuity after the phone is locked. |
BayPilot checks position age, stability and accuracy. The first few fixes confirm a stable signal. If the GPS error is too large for the zone, arming is blocked. Wait for a better reading and choose the zone size based on the safe space around the boat — do not enlarge it just to bypass the block.
Circular and directional zones
The anchor is always the reference point. The alarm compares the boat's current distance with the limit that applies in its direction.
Circular zone
One radius applies in every direction. This is the simplest choice in open water where the boat can swing freely around the anchor.
Directional zone
The small distance applies all around the anchor, while the larger distance applies only inside a selected sector. It is useful when one direction has more safe space than the others.
See the distance before arming
After setting the anchor, “Distance from anchor” updates as the boat moves, even before you select “Arm alarm”. “Allowed distance” immediately reflects changes to the zone settings. This helps you choose a limit, but the preview alone does not mean monitoring is active. The GPS distance shown is not a measurement of the chain paid out.
“Stop alarm” ends monitoring and removes the anchor, zone and completed session’s track from the map. The white dot showing the current position remains visible. The last anchor and settings stay saved locally for “Resume alarm”. This record belongs to the device or browser profile — it does not automatically transfer to another phone.
Background operation
| Platform | After lock or sleep | Recommendation |
|---|---|---|
| Android | Yes — the alarm uses a native foreground service even with the screen off. | Allow location and notifications, and check battery restrictions. |
| Computer | Not guaranteed after the computer sleeps or the browser is suspended. | Prevent sleep and keep BayPilot open. |
| Mobile web | Not guaranteed after screen lock or browser-tab suspension. | Keep BayPilot on screen; use the Android app for longer unattended monitoring. |
Device roles
Roles apply only to remote notifications. The local Anchor Alarm can be armed without selecting a role.
Monitors the boat
This device runs the local alarm, reads GPS/NMEA, sets the anchor and zone, and decides whether the boat is safe. It can send its state to receivers.
Is a receiver
This device receives notifications and a read-only map view. It cannot change the anchor or zone or stop the monitor's alarm. It can mute sound for one minute on itself or stop its own receiving session.
Personal devices and pairing different accounts
Devices on the same account
- Sign in to the same BayPilot account on all devices.
- On the device by the boat, select “Monitors the boat”.
- On the other devices, select “Is a receiver” and allow notifications.
- The monitor selects ready receivers before enabling remote notifications. No code is needed.
A receiver on another account
- The monitor selects “Add paired receiver” and gives the six-digit code to a trusted person.
- The receiver signs in to their own account, selects “Is a receiver”, enters the code and confirms the connection.
- The code is single-use and valid for 10 minutes. It connects only the device on which it was entered.
- Pairing alone does not arm the alarm. The monitor still selects the receiver when starting a remote session.
- Arm the local Anchor Alarm on the monitor.
- Select receivers from the list.
- Choose “Enable remote notifications”.
- The receiver confirms with “Receive”.
How many devices an account can handle
Personal-device, permanent-pairing and per-session limits are counted separately.
| Item | Limit | Explanation |
|---|---|---|
| Active monitor | 1 | An account can have one device running a remote session at a time. |
| Personal receiver devices | up to 5 | Phones or browser profiles signed in to the same account. |
| Paired receivers from other accounts | up to 5 | Permanent active connections created with a code. |
| Receivers in one session | up to 5 total | The sum of selected personal and paired receivers, not 5 + 5. |
| Active receiver session | 1 | One receiving device cannot follow several alarms at the same time. |
Before leaving the boat
- Check that the anchor marker is in the correct place on the map.
- Match the zone to chain length, depth, wind, current and the space around the boat.
- Wait for a stable position and test sound and notifications.
- On Android, check permissions and battery level; on the web, keep the device active.
- If receivers are used, make sure they show “Ready” and have confirmed receiving.