Alternator Pulley squealing

The alignment appears really good, checked it with a straight edge. I put a new belt just use the boat Sunday, but I'm ordering a new alternator today. No issues on that side but I have a reoccurring issue that's driving me crazy while running warm at idle.

Thanks everyone that's what I feared. All of the pulleys are smooth without wobble, but looks I'll add a new alternator to the list.

Sounds like your Alternator is worn out. Bearings shot. A rebuild or replacement is necessary. If you refer to your raw water intake pump it will turn stiff as you turn it because you are rotating the rubber impeller blades. The Engine water pump which sits at the front center of the engine above the crankshaft pully will have a little drag but turn smoothly with no wobbles if in good shape.

I have a 96 Sport Nautique GT 40 with the original alternator. I've been noticing some grinding noises like bad bearings come from one of the pulleys. Now yesterday the belt alternator belt broke, so I took the other belt off to check all the pulleys. None of them make any noise and free spin except the alternator squeals during free spin. I also noticed the water pump is hard to turn is that normal? So the question is should I replace the alternator pulley or just replace the belt and move on. If it helps I think the belts are old I bought the boat 4 years ago and have not changed them.

Thank you