I have an Eagle FishEasy 2 transom mounted on a 15'Bassmaster fiberglass bass boat. I have a fair amount of interference showing up on the screen even when stopped and the outboard is not running. Also, I can't get over half of wot before it loses its signal. I spoke with a representative from Eagle at a local show and he thought it was mounted too high. I really can't lower it any more so he recommended a shoot thru-hull transducer. How much do I need to grind the inside of the hull before I install it? Any other tips for the best results? Most of the posts on this topic spoke poorly of this type of installation, do I need to avoid it and just deal with my present situation?