## Monitoring Settings (Ground check settings)

```{important}
**Designed for configuring parameters of navigational hazard highlighting on ENC, monitoring sector width, and navigational hazard monitoring lane.**

Monitoring of navigational hazards, the safety contour in the vessel's lane, and their display on the off-scale hazard indicator are performed regardless of the ENC display highlighting state.
```

Before using ECDIS, configure the hazard monitoring parameters in the sections: **Ground check** and **Alarm filter**.

### Accessing settings

| Menu path |
|-------------|
| {{ menu }} → {{ settings }} → **Grounding check** → **Settings** |

### Monitoring configuration parameters

![Monitoring settings window](images/Ground_Check_1.png)

| No. | Parameter | Description |
|---|----------|----------|
| **1** | **Safety contour** | Selected from among the depth contours of the largest-scale ENC cell at the vessel's position with the nearest value greater than the safety depth |
| **2** | **Safety depth** | Calculated based on the current vessel draft and current water level |
| **3** | **Safety height** | Calculated based on the current vessel draft and current water level |
| **4** | **Draw Safety Zone** | Enables display of the calculated navigational safety zone |
| **5** | **Draw Sector** | Enables display of the hazard monitoring sector |
| **6** | **Set objects filter** | Opens the **Alarm filter** window |
| **7** | **Detection time (Forecast)** | Performed either by time (dynamic forecast) or **Detection range** by a set distance (static forecast). Depending on the navigator's preference, enter the value in the numeric field: time in minutes, or distance in km/nautical miles. Based on the set parameters, the radius of the hazard scanning sector ahead of the vessel will be formed.<br>![Forecast method](images/Detection_Time.png) |
| **8** | **Sector angle** | Sets the width of the hazard scanning sector. The sector is calculated relative to the vessel's course vector. The full sector angle is entered. |
| **9** | **Draw Alert Limits** | Enables display of the alert generation boundaries for detected navigational hazards — the dynamic maneuvering lane |
| **10** | **Alert priority** | Select the alert category for detected navigational hazards: **Warning** or **Caution** <br> ![Alert priority](images/Alert_Priority.png) |
| **11** | **Account the ENC Accuracy** | Enables automatic accounting of CATZOC from the largest-scale ENC under the vessel's position. ECDIS accounts for **CATZOC** values of categories **A1** and **A2**. If the **CATZOC** value exceeds **A2** (RMS > 20 m), ECDIS uses the manually entered **CATZOC** value in calculations |
| **12** | **---** | Current **CATZOC** value, **CATZOC** category, and the corresponding positional accuracy of underwater topographic features |
| **13** | **Manual input** | Manual entry of the **CATZOC** value. The value for **CATZOC** > **A2** (RMS > 20 m) to be accounted for in calculating the maneuvering lane and navigational safety zone |

```{tip}
When navigating in areas with abundant navigational hazards at low speeds, it is recommended to set the forecast method **by time** for the monitoring sector and dynamic lane.

In this situation, selecting the forecast method **by distance** may result in excessive clutter on the ENC with highlighted hazards and loss of situational awareness.

When selecting the **Detection Time** method at high speed, the scanning area will increase and the load on ECDIS will be significantly higher, which may cause user interface response delays, especially when navigating in areas with abundant navigational hazards. This is due to the large volume of objects being processed on the ENC. The most optimal monitoring method depends on the vessel's characteristics and the navigation area.
```

#### Maneuvering lane calculation

The maneuvering lane is calculated using the formula:

$B_{t} = L\sin(drift) + B\cos(drift) + t_{c}\sin(drift)V$

<!--$V_{tw} = \sqrt{{STW}^{2} + V_{aw}^{2} - 2STWV_{aw}\cos\left( K_{aw} \right)}$

$K_{tw} = HDG + K_{aw} \pm KK$

$KK = arccos\left\lbrack \frac{\left( V_{aw} - STWcosK_{aw} \right)}{V_{tw}} \right\rbrack$ -->

where:
- **$L$** -- length of the vessel or tug-barge combination, in meters
- **$B$** -- beam of the vessel or tug-barge combination, in meters
- **$drift$** -- current drift angle of the vessel
- **$V$** -- current vessel speed, in m/s
- **$t_c$** -- lead time equal to 180 seconds, in sec.

#### Navigational safety zone calculation

$AL = B_{t}\sqrt{m^{2} + c^{2}}$

where:
- **$B_t$** -- vessel maneuvering lane width
- **$m$** -- current root-mean-square error of the vessel's position, entered manually by the user or received from the `$--GSA` sentence
- **$c$** -- current **CATZOC**

### Alarm Filter configuration

Configure the highlighting of navigational hazards on the chart in the **Alarm Filter**.

| Menu path |
|-------------|
| {{ menu }} → {{ settings }} → **Grounding check** → **Alarm Filter** |

![Alarm filter](images/alarm-filter.png)

| No. | Parameter | Description |
|---|----------|----------|
| **1** | **Navigational hazards** | Enables/disables monitoring of point objects with a navigational hazard attribute |
| **2** | **Areas with special conditions** | Enables/disables monitoring of objects in the group |
| **3** | **Areas with special conditions** group | Detail of objects in areas with special navigation conditions |
| **4** | **Safety contour** | Enables/disables monitoring of the safety contour |
| **5** | **User defined areas with special conditions** | Enables/disables monitoring of objects belonging to the group |
| **6** | **User defined areas with special conditions** group: <br>- Information areas (Anchor Berth, Cargo transhipment area, Fishing ground)<br>- Protected areas (Dumping Ground, Incineration area, Pipeline area, Precautionary area, Cable area, Fairway, Territorial sea area)<br>- Ships routing system and ferry routes<br>- Miscellaneous (Depth contour, Continental shelf area, Exclusive zone) | Detail of objects in user-defined areas with special conditions |

### Configuration recommendations

**Before configuring monitoring:**
1. Ensure the current {doc}`vessel draft </sections/vessel-settings/vessel-dimensions/index>` is set correctly
2. Verify the sensor settings are correct
3. Set the current water level for correct selection of safety contour and safety depth

**Safety configuration:**
1. Select the forecast method (time or distance)
2. Set the monitoring sector and lane parameters
3. Configure the object filter for monitoring
4. Enable sector display on the chart for visual monitoring

```{warning}
The use of hazard monitoring does not replace the navigator's professional judgment. The system warns of potential hazards, but the officer of the watch always makes the final safety decision.
```
