I have a 2009 22SV World Edition.

Took the boat out today, and both the analog and digital gauge showed a half full tank. After motoring for 30 minutes or so, both gauges went from 50% to 0% while I was watching. Now both gauges read empty and will not change. I shut the boat down to reset the electronics, and restarted. No change.

What steps should I be doing to troubleshoot?