Tightening the V Belt

[krra1]

I am a new owner of a 1990 Maristar with a 454 Chevy big block. This past weekend when starting the boat skeeling noise came from the engine. I notice the V belt was loose. The manual is not very clear on how to tighten this. The belt is fairly new and not worn.

Any pointer would be helpful.

[Footin]

Pretty tight with about 1/4 inch play.

[krra1]

That's about all the manual says. How do you tighten it? What needs to be done.