2006 Sportster 4-TEC, single long beep when running - overheating?

[ACABThomas]

2006 Seadoo Sporster 4-TEC boat, was running fine and then today I was cruising slowly, started to accelerate, and got a single long beep. None of the idiot lights lit up. Throttled down, tried it again, same issue. Nursed it back home at slowest speed. All my googling seems to point to either exhaust overheating or engine coolant overheating - sound correct? Is there a way to know whether it's coolant or exhaust?
Coolant in reservoir was very hot - not sure if that's normal or not. Planning to pull it out of water to check underneath for any blockages. What else should I check? Anyone have step-by-step troubleshooting for this issue? Thanks.

Update 7/5/2024: mechanic connected probe to boat to pull any codes, did not find any. He reset the computer, and the boat ran great for one day, no beeping. Next day, same issue returned. The beep is a 2-second beep, and appears to happen randomly. I can cruise for a few minutes, it will beep, keep going, then it will eventually beep again, sometimes 5 seconds later, sometime 40 seconds - random. I can continue to cruise at speed through the beeps, so it's not going into Limp Mode nor otherwise affecting the engine, it's just a loud, annoying random beep.

 

[Burner71]

It's low oil
This drove me nuts all last year.

 

[RustyBucketBay]

My 2012 challenger does a single beep like this when low on fuel. Can happen when in the lower quarter and turning hard. Or lower and going straight. And can happen prior to the “low fuel” warning light comes on.

So could be as simple as filling up.

 

[RustyBucketBay]

2012 challenger SE manual:


So as per the other comments it could be oil or possiblly any fluid. Check fuel, oil, coolant levels, top off if low. If beep persists it’s possibly a signal error on one of the sensors or something else.

FYI other than the manual mentioning warning beeps in this context here, there is no call out for fluid warning alarms in the later section of the manual. They talk about more serious alarms, overheating, non stop alarms etc. see below, re overheating that would be a continuous beep according to my manual.

 

[RustyBucketBay]

Just watched your vid again. Is the battery light illuminated? I See a red hue in the vid. Or is that something else? If it is you could be getting a warning signal for that too. Basically this 2sec beep is to draw your attention to look at the dash and/or at fluids.

 

[Burner71]

So after I had this issue for half a summer I discovered my oil was bit low and at full speed the SC was pulling alot of oil from the motor causing the beep. Months later I got the beep again, this time it was a battery that was not taking charge. Swapped batteries and it went away.

I also see a red light on your battery in the video.