Hercules (1997)

"Hades (James Woods), king of the underworld, wants Hercules (Tate Donovan) dead. He puts his best henchmen, Pain and Panic (Bobcat Goldthwait and Matt Frewer), on the job. They tell him he’s dead. And Hades believes them, for quite some time! But, as we know, they’re dead wrong. Hercules may be super strong. But Hades is, without exaggeration, the king of the underworld. Why didn’t he double check that Hercules was actually dead? Just by, like, looking around? He lives and works in the place where dead people go. Wouldn’t Hercules have shown up?"
It’s about BUOYANCY!
I agree - Rose would have floated if she was the one in the water. ????