Wookiee
Shift - D opens the multi dock to full screen.
To reiterate what was written earlier, several versions ago Sonar used to default to full screen view, or at the very least would remember docking settings when a project is saved/re-opened, but now it seems that it will default to a half-pane view regardless. Kind of annoying, but hitting Shift-D doesn't put too much of a crimp on the workflow. And what's nice is that once you've hit Shift-D after starting/opening a project, it
will remember that setting for the rest of the session, so just hitting D will toggle between screens. It's just when you start a new project or open a saved one that you have to press Shift-D. At least that's been my experience.