Humminbird 998c SI - Manual (Page 141)

131 Setup Menu Tab
When navigating, the following NMEA sentences are also output:
APB - Autopilot Sentence B
BWR - Bearing and Distance to Waypoint
RMB - Recommended Minimum Navigation Info
Sonar
Settings: Off, On, Default = On
Sonar deactivates Sonar and removes the Sonar Views from the view
rotation.
Demonstration
Settings: Off, Visible; Default = Visible
Demonstration controls whether the Demonstration Mode is visible or off.
The Demonstration Mode appears on the screen if you don’t press any keys
during the warning screen at power up. Menu settings cannot be saved in
Demonstration (see Power On the Control Head and Start-Up Options
Menu).
Sound Control
Settings: No Sounds, Alarms Only, All Sounds;
Default = All Sounds
Sound Control allows you to set when the control head will beep or sound
because of key presses and/or alarms.
Video Out
Settings: Domestic Models: NTSC, Off;
International Models: NTSC, PAL, PAL M, Off;
Default = Off
Video Out allows you to set the video format that will be sent to your remote
monitor.