You can easily calculate/measure the distance between a vessel and any other Waypoint as defined by you.

To start, simply right-click anywhere on the Live Map and select the Distance From Here option to set it as your starting point.

A yellow pin marker will be placed on the selected vessel or point on the Live Map. From this point on, you can click anywhere on the Live Map and define your waypoints.

A yellow circle appears and by dragging its center towards the endpoint of where we want to measure, we get the following information:

To exit the tool, simply right-click anywhere on the Live map and select the Exit measure distance option to clear the map and remove the Waypoints you have set.