I don't see a boat shape, but as far as the Spitz comment goes, I think there's a vast difference between a mark made by an object with an image of a boat (as the comment is being interpreted elsewhere) and describing the mark as "boat shaped."

IMO it's illogical to assume Spitz was saying a snap or button shaped like -or- with the image of a boat left the dark mark on JonBenet's face. What I think he was doing was describing an image to use as a point of reference when discussing the features of the stun gun mark - he could likewise have compared the features of the mark to one of the 50 states, without necessarily implying that JonBenet's face rested against an actual 'button or snap' with an outline of the State of Texas, for example!