PolarCOM provides an independent set of alarms including depth and anchor alarms. Our alarms provide a solid aural warning (adapted from standardized Navy alarm sound) as well as a visual warning. Both will require manual user intervention to confirm and dismiss.
Alarm functionality requires no chart view, takes no screen "real estate" while inactive and can be accessed at any time by pressing a hot key combination (Shift + Alt + A by default).
Here is an image of PolarCOM alarm pane (shown in the screenshot overlaid on the chart):