I started reading this because I was curious how a life jacket could malfunction. Like, they're just pieces of styrofoam that you wear. There's nothing mechanical, is there? But this IDIOT of a main character is using what seems to be some sort of "instant release" life jacket, which apparently can. He might as well have not been wearing one, at that level of bullsh*tery.
I have many things to say about how anyone on a boat should use an actual, standard life jacket, but I don't care enough to go over basic boating safety under a manga.