Head Hold question

Have I overlooked something or is there no head hold option on QGC or Cockpit ?

Hi @real_kiwi -
Stabilize mode in ArduSub is equivalent to heading hold, it will also work to keep the vehicle level in the roll axis, and pitch axis for 6dof vehicles.
Depth hold mode does the same, but also includes maintaining the same depth via pressure sensor. You can read more here!