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Set and monitor the anchor alarm

Use the anchor alarm to monitor the boat’s distance from a chosen anchor position. BoatKit displays a yellow warning boundary and a red alarm boundary around that position, then changes the alarm state if the boat reaches either boundary.

warning

An anchor alarm supplements—not replaces—an independent anchor-watch practice. Before leaving the watch unattended or going to sleep, review the alarm area, verify every alert path you intend to rely on, and initially observe the active watch with the chart open.

Before you start​

You need:

  • An interactive chart and administrator access to BoatKit.
  • A trustworthy GPS position. Drop anchor is disabled when no GPS position is available.
  • A current, credible depth reading for the anchorage.
  • A plan for the boat’s expected swing, including depth, tide, scope, bow or bridle height, weather, current, and nearby hazards.
  • A usable heading if you want BoatKit to calculate the catenary estimate.
  • A separately verified onboard audio path if you intend to rely on an audible alarm.
  • Working boat internet, a BoatKit Cloud connection, and verified destinations if you intend to receive cloud notifications.

Configure the calculation inputs​

These settings improve the anchor-scope and catenary estimates. Configure them before relying on the worksheet.

Enter the anchoring offsets​

  1. Open Settings > Vessel Info > Anchoring Info.
  2. Set Bow Sprit/Bridle Height Above Waterline to the height from the waterline to the point where the rode leaves the boat.
  3. Set Sounder Depth Below Waterline to the distance from the waterline to the sounder transducer.

Both settings default to zero. Leave a value at zero when it is unknown or is already included in the sounder’s depth output.

A non-zero Sounder Depth Below Waterline value overrides the active sounder’s reported transducer offset for the anchor worksheet only.

Enter each GPS antenna position​

BoatKit uses the active GPS antenna’s position to calculate the location of the center of the bow. The position is stored separately for each GPS source because BoatKit may switch among antennas installed in different locations.

For each GPS source:

  1. Open Settings > Sensors and open the source’s GPS configuration dialog.
  2. Find GPS Installation Position.
  3. Leave Use vessel center selected if the antenna is at the vessel center. This is the default and uses half the configured vessel length and beam.
  4. Otherwise, clear Use vessel center and enter the antenna’s Distance aft of bow and Distance from port side.
  5. Save the GPS configuration.

Make sure the vessel length and beam under Vessel Info are accurate if you use the vessel-center default.

Verify the alert paths​

Onboard monitoring and sound​

BoatKit evaluates the anchor boundary aboard the boat. Audible output depends on the attached audio hardware and its configuration.

The Viewer does not currently provide a dedicated, safe local anchor-alarm sound test. Before relying on an unattended watch:

  1. Verify the attached audio hardware using its supported device procedure.
  2. Keep the chart open while first observing the active watch.
  3. Retain an independent anchor-watch practice.

Do not move the anchor center or shrink the boundaries of a live watch merely to force a warning or alarm. A BoatKit Cloud notification test does not test the onboard sound path.

BoatKit Cloud notifications​

Cloud notifications are optional and supplemental. They require working internet aboard the boat, an active BoatKit Cloud connection, and a verified notification destination.

Open Settings > Notifications > Vessel Notifications.

For the current mobile device:

  1. Enable Notifications & warnings.
  2. Enable Alarms.
  3. When available, enable Use Critical Alerts if BoatKit must be able to alert through Focus or Do Not Disturb settings.

To add SMS or email delivery:

  1. Select Add SMS or Add email.
  2. Enter the phone number or email address.
  3. Select Notifications & warnings, Alarms, or both.
  4. Select Send verification code.
  5. Enter the six-digit code you receive.
  6. Select Verify and add.

Select Send test warning and Send test alarm, then confirm receipt at every destination you plan to rely on. These buttons test BoatKit Cloud delivery only. They do not test the anchor-boundary calculation or onboard audible output, and they do not guarantee delivery during a later internet or cloud outage.

Set the anchor watch​

  1. Confirm that the chart shows a stable, credible boat position and that the sounder reading is reasonable for the anchorage.
  2. On the interactive chart, select the anchor toolbar button labelled Drop anchor.
  3. In the Drop anchor? dialog, confirm Drop anchor.
  4. Review the center and both proposed boundaries before relying on the watch.
  5. Drag or touch-drag the anchor handle if the center needs to move to the actual anchor position.
  6. Drag the yellow radius handle to set the warning boundary.
  7. Drag the red radius handle to set the alarm boundary.

BoatKit initially places the center at the boat’s current position and proposes warning and alarm radii from the available depth information and applicable sounder offset. Minimum radii prevent zero or missing depth from producing an arbitrarily tiny watch area. The proposed values are starting points, not a substitute for your judgment.

Keep the yellow warning circle inside the red alarm circle. Choose both radii with the expected scope, depth and tide, bow or bridle height, anticipated conditions, room to swing, and nearby hazards in mind.

On a normal connection, releasing a handle immediately saves that center or radius change. There is no separate save step.

Confirm it is working​

After the watch is armed, confirm all of these visible results without deliberately crossing a boundary:

  • The anchor toolbar button is red and is relabelled Weigh anchor.
  • The chart shows the anchor handle.
  • A yellow warning circle and its radius handle are visible.
  • A red alarm circle and its radius handle are visible.
  • A tether runs from the boat to the anchor center and shows the current distance.
  • The Anchor scope worksheet appears near the lower-right corner.

Continue watching the position and distance while the boat settles. Reassess the center and radii if the actual set, conditions, or expected swing differ from the plan.

Use the anchor-scope worksheet​

While the anchor watch is set, the worksheet shows:

  • The current sounder reading.
  • Any applied sounder offset.
  • The maximum additional tide rise predicted during the next 24 hours.
  • Any configured bow or bridle height.
  • The resulting total vertical distance.
  • Rode lengths for 3:1, 5:1, and 7:1 scope in your selected length unit.

Scope is the ratio of rode length to the total vertical distance from the seabed to the point where the rode leaves the boat.

If required depth or tide information is unavailable, BoatKit shows the affected values as unavailable (—) instead of treating missing data as zero. The worksheet may shift from the lower-right corner to avoid covering chart controls and reserved areas at the edge of the display.

The 24h tide rise row links to the tide station used by the worksheet. Select it to center and zoom the chart on that station, highlight the station, and open its normal tide ticker. Selecting the row does not also select the chart underneath the worksheet.

Interpret the catenary estimate​

A catenary is the curve formed by a freely hanging rode. The worksheet’s estimate combines:

  • Chart depth at the anchor position.
  • The predicted current tide height.
  • The configured bow or bridle height.
  • The live horizontal distance from the center of the bow to the anchor.

BoatKit derives the bow-center position from the active GPS source’s configured antenna position, the vessel length and beam, and the current heading. Without a usable heading, the dependent distance and catenary estimate remain unavailable.

When the chart supplies a depth range rather than a single depth, BoatKit uses the deeper bound. Drying areas and locations without usable chart depth do not produce an estimate.

The displayed Chain length models a freely hanging rode that is tangent to the seabed at the anchor. It does not account for chain weight, seabed characteristics, wind, current, snubbers, or the amount of rode actually deployed. Treat it as a planning check, not an instruction for how much rode to deploy.

End the watch​

When you intentionally end the anchor watch:

  1. Select Weigh anchor on the chart toolbar.
  2. In the Weigh anchor? dialog, confirm Weigh anchor.
  3. Confirm that the anchor geometry and worksheet are no longer shown as an active watch.

Offline and LoRa behavior​

BoatKit continues evaluating the anchor boundary aboard the boat without an internet connection. BoatKit Cloud notifications do not continue while the boat is offline or disconnected from BoatKit Cloud.

In the constrained LoRa Viewer, you cannot drop or weigh the anchor. If an anchor watch is already active, you can edit its center and radii. Those edits remain a draft until you select the separate Save button.

Troubleshooting​

Drop anchor is missing or disabled​

  • If the button is missing, confirm that you are using an interactive chart with anchor controls and that your account has administrator access.
  • If the button is visible but disabled, check whether BoatKit currently has a GPS position.
  • Do not arm the watch until the displayed position is trustworthy.

The proposed area does not fit the anchorage​

BoatKit’s proposed radii are only defaults. Check the current depth, the values under Anchoring Info, the expected tide and scope, anticipated conditions, and nearby hazards. Then reposition the center or resize each circle with its handle.

Worksheet values show —​

A dash means an input or dependent result is unavailable, not zero. Check the current sounder data and the availability of a nearby tide prediction.

For a missing catenary estimate, also check that:

  • The chart has usable depth information at the anchor position.
  • The current tide prediction is available.
  • BoatKit has a usable heading.
  • The vessel dimensions and active GPS antenna position are configured correctly.

Cloud tests do not arrive​

  • Confirm that the boat has internet access and is connected to BoatKit Cloud.
  • Confirm that the SMS number or email address was verified.
  • Confirm that Notifications & warnings and Alarms are enabled as needed.
  • On a mobile device, check BoatKit’s notification permissions and, when supported, Critical Alert permission.
  • Send the tests again and confirm receipt on every destination you intend to rely on.

No onboard sound is heard​

A successful cloud test does not verify local audio. Check the attached audio hardware using its supported device procedure. Do not force a live boundary event by moving the center or shrinking the watch area.