Vixen
Penultimate Amazing
A bow visor is part of the hull. Where do you think the hull stops and the superstructure starts?
The car deck is part of the hull, it is not part of the superstructure.
The different types of what is commonly called the hull can be seen here and is clearly what rests in the water. The bow visor is nowhere near the waterline.
Here's what the JAIC says about (a) the hull and (b) the car deck, which is clearly part of the superstructure.
The hull below the bulkhead deck was subdivided by fifteen watertight transverse bulkheads, equipped with watertight doors as required.
The double-bottom spaces were arranged for fuel oils and other liquids and some were designated as empty tanks. Fuel oil tanks were also placed above the inner bottom.
Deck 0, the tank-deck, contained- from forward - the forepeak, the bow thruster room, an extensive sauna and swimming pool area and - in the aft half of the ship - the generator room, the engine room, the fuel purifier room and other machinery-related spaces. The deck next above, deck l, contained - in the forward half - economy class cabins for 358 passengers. The aft half of the deck contained the engine control room, workshop, main engine room and various utility spaces.
The car deck was one open space, with the exception of a centre casing, located slightly to starboard. Loading ramps were arranged one at the forward end and two at the aft end of the deck. The centre casing contained staircases from the spaces below the car deck, lift trunks and various utility spaces for machinery and catering functions. Five lifts were installed, extending from the passenger spaces below the car deck and from the car deck to deck number 7.
The car deck was on deck one, some two floors up from the hull below the bulkhead. As it was above the waterline it is not considered to be part of the bullkhead hull.