Digital multi-function gauge reading

I have two multifunction gauges on my boat. The one I have a question on is the one which indicates fuel, time, and charging. Sometimes when I am running the charging portion flashes something over 16 volts (never more). When idling, it is usually over 13 or at about 14. Why does it flash at 16.2 or so and does the flashing indicate a problem?

Go Gators!
Thanks

[boats.net]

It's indicating a high voltage reading. Check charging system.