>>715771483 (OP)
Don't let him lead you to the land he understands, that's his opening attack and will follow up with a trip to the corner of the glove if he takes you by the hand, block to avoid the crust but only if you have a high enough level, the crust is elusive otherwise.
Ocean man will stop attacking and will see at the wonder of amazement, just close in and attack as much as you can.
Finally, you must break the sequence of life in order for ocean man to not soak up the thirst of the land, which will recover his HP and buff him, making the fight harder and last longer.