Re: 17' Sportsman Alarm sound or bad relay?
This is probably the "overheat" alarm. This alarm sounds when your engine is getting too hot. You need to verify if you are getting water spray from the ports on the back of the engine leg.
If the alarm is sounding, you either have a bad water pump impeller, bad thermostat, or a blockage in the water path. I would also look into installing a tell-tail.
If you look at my restoration thread in the link below, you should find a picture of what the alarm looks like. I had the same question about the alarm back then.
Let me know if you have any further questions.