When we brought our last boat home we traveled 1,400 miles. It was a twin engine trawler, sorta. It had a small keel that went down about 4 or 5” below the props. Coming up the Hudson River we hit submerged objects over 15 times. We drove that boat from the flybridge and some of the strikes would shudder the boat all the way up to the flybridge. I was extremely concerned about the props and rudders. When we got to the Big Chute I asked the lockmaster to look at my props and rudders to see how bad they were. He said there was no damage which I confirmed when we hauled for the winter. My point being that if you have some keel sticking below the props you may never have any issues, but you might. After that trip I didn’t worry so much about submerged debris. Our current twin engine boat has no keel and the props have absolutely no protection so I worry about it now.