How he got there, he couldn't think straight to remember, but the only thing he could focus on was the burning sensation in his lungs as they filled with water, unable to break the surface quickly enough, he felt his body grow weak, unable to swim, his vision blurring... He was drowning.

Overhead, he could just barely make out a small rowboat on the ocean surface, with no way to call for help, because well... He's underwater and his lantern flame is extinguished, he has to hope and pray. He sees a figure submerging into the water, which was good, that meant they had found him.

Meanwhile, you had been out on your rowboat at sea when you had seen a strange silhouette under the water. It looked like a person, so naturally you put your oars down and dove in, and you were correct, you see a man with long blue hair sinking clearly, drowning.