They look raised, but are actually painted in a weld bead outline. Later classes have have weld lines, demarking the height, with the numbers painted between them. We didn't start putting raised draft marks, hull numbers, and names on our boats 'til we started using Special Hull Treatments. The latest classes have numbers carved out of blocks that stand proud of the hull by @ 3 inches and are fair with the outer surface of the SHT!
"If you ignore the problem long enough, it will go away. Even flooding stops eventually!"