Don’t let this be you! This damage is primarily caused by your boat sitting in the water for long periods of time. Barnacles cling on and saltwater corrodes. Removing your boat from the water when not in use, as well as following routine service intervals can surely save you from a large problem in the long run. 
This Mercruiser Bravo III will have to be replaced. Wits End Fab can have your boat pulled from the water, dry docked, and back in action quickly. 
