## Features

During ECDIS operation, situations arise that require the navigator's attention. An alert system is implemented to draw attention. The most important notifications must be acknowledged by the operator.

**Notification types:**
- ![](images/icon-alarm.png) **Alarm** — requires immediate response. An alarm can also be an escalation of an unacknowledged warning status. When an alarm is generated, a triple audible signal is sounded.
- ![](images/icon-warning.png) **Warning** — a situation requiring attention to prevent the deterioration of conditions; if the navigator does not respond, a **Warning** may escalate to an **Alarm** status. The audible signal is double.
- ![](images/icon-caution.png) **Caution** — requires attention under the current circumstances.
- ![](images/icon-info.png) **Informational notifications** — general messages about the start/completion of processes, do not require acknowledgment.
- ![](images/icon-persistent.png) **Persistent messages** — used to display {doc}`SSE25, SSE27 </sections/enc-collection-management/sse-messages/index>` messages and "Unofficial chart".

Alerts are displayed as pop-up rectangular indicators in the notification area.

### Alarm acknowledgment

To acknowledge a notification — press `ACK` in the alert log row or use {doc}`keyboard shortcuts </sections/graphical-user-interface/hot-keys/index>`.

![](images/Alert_Log.png)

### Alarm and warning statuses

- **Active-unacknowledged** — the alarm is current and unacknowledged.
- **Active-silenced** — the alarm is current, unacknowledged, and the sound is muted.
- **Active-acknowledged** — the alarm is current and acknowledged.
- **Responsibility transferred** — the alarm is current, unacknowledged, and transferred to the BAM.
- **Rectified-unacknowledged** — the condition has been resolved, but the alarm has not been acknowledged.
- **Active** — the alarm condition is current.
- **Normal** — no alarm condition is present.
