Leviathan (1989) is directed by George P. Cosmatos. Cosmatos also directed Cobra (1986) (a film I'd never seen until last week, but that I now rank among my favorite action films), as well as Tombstone (1993) and Rambo: First Blood Part II (1985) (though claims abound that Kurt Russell and Sylvester Stallone, respectively, ghost directed those films).
As far as I can tell, no one is claiming that any of Leviathan's stars (which included Peter Weller, Daniel Stern, and Ernie Hudson) wrestled directorial control away from Cosmatos. I've never seen the Alien-esque Underwater Terror flick, but am curious to check it out, especially after seeing the film's beautiful minimalistic poster.
Click through for Leviathan's full poster and a trailer.