Warning alarm sounding when oil tank is full.

I have a late 80s 3 cylinder 90hp mariner, when I took it out to sea within 5 minutes a beep beep beep alarm started coming from the control box, I thought it was and overheating alarm so I turned off the engine and felt how hot it was. The top of the engine felt qiute hot even though there was a good pee stream coming from the engine so we rowed to shore, a few hours later when the engine was cold I started it again and the beeping started as soon as I turned the key. I have read on the internet that the overheating alarm is a continous beep, and a beep beep beep is the oil alarm. My oil tank is 3/4 full. I have only just bought this engine and I dont know to much about engines, and Im quite worried that it is broken, so any help would be much appreciated.
Why is the alarm going off???
Why is my engine getting hot even though there seem to be lots of water going through it???
Is my thermostat broken???

Re: Warning alarm sounding when oil tank is full.

The beeping is a oil alarm, if there is oil in the tank unplug the 2 blue wires that come out of the bottom of the tank and the beeping stops the magnet has fallen off the float in the tank and the tank will have to be replaced.

Re: Warning alarm sounding when oil tank is full.

Ok thanks Laddies I will give that a try, and I will let you know how it goes. Thank you.

Re: Warning alarm sounding when oil tank is full.

Exellent that seems to have sorted it. Thank you very much for your advice