This was just like the buggy in Nemesis, something that's never been seen in Trek before so therefore it must be new, different and cool. Totally pointless I found.
I've been a fan for thirty-seven years and sometimes I can enjoy cool just because it's cool. Is the Enterprise
being underwater problematic from a logic perspective? Sure. But it doesn't stop me from drooling when it rises up out of the ocean, flies towards the volcano then zips away like a fighter jet.
But then again, I always liked the dune-buggy scene in "Nemesis".