Context
Each marker is positioned based on the two known axes in the view as well as the tilt and bearing of the current ping.
ExampleWhen you are manoeuvring close to the coastline, or in otherwise working in confined waters, you may wish to avoid shallow
waters and reefs. To keep track of potentially dangerous places, you place markers on them.
The marker is stationary. It has a specified range, bearing and depth related to your own vessel. If the echo moves in the ST90 presentation the marker will not follow.