Ok, I just finished installing my Humminbird 525. My boat is an older, fiberglass narrow hull boat. I mounted the transducer about 15 inches from center of the boat, not from the edge of the prop. Will this be ok or do I need to go farther out? The problem I have getting farther out is there is a small plastic fin with a hole in the end of it (kind of like a pitot tube on a plane) right on the edge and the boat is a tri hull so I dont want to mount it on the far edge because of fear of turbulence. Thanks for any help.