When I was attacked by Sealnado, he did his attack where he pulls you in but he never spat me back out. The screen was locked on one location and although my character still commented on his increasing water level his model was missing . I managed to bypass this issue by quitting the game and reloading the save.
Step 1, get attacked by sealnado. Step 2, stand still while attacking him constantly. Step 3, wait for him to use his pull in attack. That's how it happened for me at least