well like the quote Acelancelot posted by me from the past, "follow the lines of the hull as..." means that one must try to present the hull as accurately as possible. Thus if the ship has bulge, it should be shown someways so the 2nd drawing of your last post would be most correct one. Generally the rules about the underwater hulls applies to the more sleak modern combatants which doesen't have bulges. When drawing pre-dreadnougths, one has to venture to bend them rules little bit