2001 Mercury 125 engine alarm

[nim713]

I'm new to mercury and just bought a new to me crestliner sportfish 1850 with a 2001 mercury 125. The motor has less than 100hrs and was always well maintained and serviced. While out today, I ran it for a bit, shut it down to fish. When I restarted it I put it in gear and drove a bit but at low throttle. I put the throttle all the way down than the alarm sounded. The alarm will shut off when it levels out on plain. Any thoughts on why?

 

[Faztbullet]

Check oil tank level