'84 120 mercruiser engine squealing and loss of power

Hi, tonight while on the water, my mercruiser started squealing first at an idle and then stayed squealing as we headed back toward shore. I noticed that if the throttle was more than half throttle it had a significant loss of power. by the time we got back to shore 10 minutes later, it was hesitating and showed a loss of power even at low throttle/rpm. The hesitation felt like a clogged fuel filter or bad gas, but it was too coincidental to both happen at the same time. As I got back to the dock, 2 ladies were standing there and both said, "thats too bad, sounds like you lost your bearing, it wont fix itself". How do I tell if this is my crank shaft bearing or something else? I thought it might be the belt, but the alternator was charging the battery fine, also the battery is very strong and cranked well. Any advise would be appreciated!

Ayuh,.... Pull the outdrive, 'n try it... just so's ya know whether it's the motor, or the drive...

Have ya checked the fluids,..?? drive oil,..?? motor oil,..??

Squealing from the engine is most likely a seized wrist pin in a piston.

What was the reading on the oil pressure gauge? crank bearings usually knock...