Create AI system of a shark inside the ocean and it chases the player to attack

I’m creating a system where a shark chases the player into the water to attack him. I managed to create the function in which he chases the player, but I used Character BP for the shark, so he just swims close to the ground. I would like him to swim in the Z position too, from what I’ve seen he doesn’t understand the Z axis.
Thanks in advance.