for anyone playing this on a computer and wondering where the fuck the "B" "A" and such buttons can be found, namely what the controls are in general as there is no menu explaining them:
on my german qwertz keyboard, I had to use 3 buttons:
the L key (yep, I mean the letter L there),
the one with , and ; on it and
the one with . and : on it
on my keyboard, the last 2 ones are directly below the normal L key.
you will also realize that despite looking like they do the same, 2 of these buttons are used to dive but one of them has some certain effect on the environment. what I mean will make sense once you get the corresponding upgrade and wonder why tf the normal dive doesnt do. then you will wanna use that second key instead :-)