thank you very much for playing and +1 thanks for recording gameplay.
the shark has 2 different dashes based on context. out of water it will go in whatever yaw direction you input (or forward by default), but underwater you will just go in the direction you are currently diving. the idea is that you dash underwater before you leave a water-sphere so you can launch yourself out of water in any angle (mostly upwards).
you are correct that i need to tutorialize better. i lean pretty hard to "let the player figure stuff out" and i saw it working for that section in the rain, but explaining the dive-mechanic needs some more attention it seems.