Stipulating to the entire scenario, I can’t believe that the diver assassin would have bright yellow gear.
I think it’s legs and feet of a person floating on their back.
Maybe somebody can find the type of shoe with that sole and put this to rest.
I also note that there appears to be something black near one of the other passengers floating in the background.
One of the 9 people on board? Any opinion as to which one? All constructive input is good.
Are we sure that a diver would be an assassin, if it was a diver?