I used the standard size, mounted to a piece of varnished mahogany with short wood screws, because I felt that provided more contrast to highlight the emblem than just mounting it on the white hull.
http://i188.photobucket.com/albums/z...ipics006-1.jpg I used No. 10 machine screws to mount the wood to the boat, via drilled and tapped holes in the fiberglass. I always mount stuff to fiberglass this way if I'm not thru-bolting it, because the machine screws stay tight; DON'T use sheet metal screws . . . the sharp edges on the threads act like knives and will eventually cause the screws to loosen up! No sealant or 5200 is required.