Could someone tell me the best method for drilling large holes in a fiberglass boat? According to the instructions with my new lowrance unit, I have to drill a 1" dia hole to run the power and transducer cables through. That's an awfully large drill bit. Would a hole saw work best for this? I only want to do this once and get it right the first time so any tips would be greatly appreciated. I plan to bring the cables up through the top cap right next to the console. Thanks in advance.