not only is this the first carrier with a deck mounted 16" turret
The HMS Furious in 1917 had both a rear 18" turret and a flight deck at the same time, though it might be questionable as to whether-or-not it’d qualify as an aircraft carrier (though the concept of an “aircraft carrier” was pretty embryonic in 1917, so some allowance probably has to be made). And while the turret was on a deck, it wasn’t on the flight deck.
The HMS Furious in 1917 had both a rear 18" turret and a flight deck at the same time, though it might be questionable as to whether-or-not it’d qualify as an aircraft carrier (though the concept of an “aircraft carrier” was pretty embryonic in 1917, so some allowance probably has to be made). And while the turret was on a deck, it wasn’t on the flight deck.
I thought the “18” was a typo, but the Royal Navy really did put the heaviest gun they ever fielded on a carrier.