Excess exhaust in my 2002 malibu

Hey guys... been having some excess exhaust from my boat lately. as far as I can tell, the boat feels like it's running great... and I don't notice the exhaust until I stop to pick up a rider... while pulling people everything looks fine... what might cause excess exhaust??? Thanks for any info!

Everytime? Is there a slight tail wind? Weird!

yeah... that's what everybody says. it happens every time I go... I just hope I'm not hurting my boat without knowing it. like I said, it runs fine as far as I can tell. ???

how many hrs on the motor that could be a tell tale sign of rings or valves leaking oil by most people wont ever smell the exhaust unless its got some oil mixed with it that gives you the most disinct smell. another thing to note is what color is when sitting still if you can tell

Exhaust manifold gasket....