Err ... you know that Panerai was used by the italian navy divers. But that was from 1935 till the 50s. After the release of Blancpain Fifty Fathoms in 1953, followed by Rolex Submariner in 1954. Both set the default standard for diver watch, even till today.
Do the Italian Navy diver still use non rotating bezel diver watch today? I think the answer is likely a no.
Moreover, one of the criteria of ISO 6425 (1996) stated the presence of a unidirectional bezel with at least at every 5 minutes elapsed minute markings and a pre-select marker to mark a specific minute marking.
I have a Citizen Royal Marines Commando BN0110-57E, which can goes up to 300m WR. But without the rotating bezel, I cannot regard it as a diver watch, even if it can go down to 12km.
Again, if Maria did not start with Bull Shark being a homage of the 1954 vintage Rolex diver 6204, I would not bother to give any comment. But being a member of this forum, I feel that I have the responsibilty to do so, if the design is deviated too far from the original intended design.
No problem, if you still think the fixed bezel Bull Shark is a diver watch, so be it. Your wrist, your money, I don't want to judge.