## Chart Scaling

The **Chart Scaling** tool allows you to zoom in or zoom out an arbitrary area on the chart. It is activated through the context menu or the tool selection menu.

### Tool activation

The tool is activated by clicking the scaling icon ![Scaling](images/zoom-icon.png) in the tool selection menu. When activated, the ECDIS cursor changes to ![Scaling cursor](images/zoom-cursor.png)

### Zooming in

**To zoom in on an arbitrary area of the chart:**

1. **Using the mouse:** press and hold the left mouse button at any point on the chart and, without releasing, move the cursor in the south-east or south-west direction, defining the selection area (orange frame).
2. **On a touchscreen:** touch the screen at a point on the chart and, without releasing, move your finger in the south-east or south-west direction.

The area bounded by the frame will be zoomed in and fitted to the chart window dimensions.

![Zooming in](images/zoom-in.png)

### Zooming out

**To zoom out of an arbitrary area on the chart:**

Perform the same actions as for zooming in, but with different frame construction directions: **north-east** or **north-west**.

The area bounded by the frame will be zoomed out.

![Zooming out](images/zoom-out.png)

### Operating features

**Directions for scaling:**
- **Zoom in:** cursor movement in the south-east or south-west direction
- **Zoom out:** cursor movement in the north-east or north-west direction

**Visual indication:**
- The selected area is displayed with an orange frame
- After releasing the mouse button or finger, scaling is applied automatically

```{tip}
**For precise scaling, select an area corresponding to the chart section of interest.**

The scaling tool is especially useful when working with detailed chart areas or when you need to quickly switch to an overview.
```

```{note}
The direction of cursor movement determines the operation (zoom in or zoom out). Remember: southward direction — zoom in, northward direction — zoom out.
```
