It's a bit application specific, i use it for plotting targets from Trackpoint II plus echo sounder.
TP locates underwater targets using transponders.
By attaching a transponder to a diver, ROV or even
fish you can track it from the surface with descent accuracy (a few meters)
There is a link on my webpage about Trackpoint, it's quite old but still works.
https://stadar.org/content/opencpn-plugin-trackpoint-ii