In response to "after the first screw"
Had a 2556 Bayliner in here for engine work. I walk by, and notice dimples protruding out of the glass on the port side. Closer examination reveals pointy ends of screws sticking out side of hull, halfway between chin and sheer, all in a nice row, spaced about a foot apart.
"Hmmm" I says, "wonder what the reason for that is."
I crawl in the boat, and the woner has installed an electrical wire to provide an outlet on the port side. Making this a clean install, he ran the wire on the underside of the dinette, inside the berth area. Then he ran screws into the hull to hold the wire clamps to support the cable.
If he had positioned the screws going up, he would have screwed into 1/2" plywood. ANd it would have been an easier position to get the drill into. Instead, he turned his drill 90 degrees, and screwed into the mucj thinner than 1/2" hull.
He did, however, uses stainless screws.