Director-producer Sean Cunningham molds this tale of a sea monster attacking an ocean-bottom research team [story by Lewis Abernathy].
Crew, while trying to create a level launch site for some ocean-floor navy missiles, blows up a cavern in which the creature has been dwelling for eons. Enraged, it attacks their craft, manages to get inside, and more or less picks them off one by one.
But effect is diluted by implausibility, as creature never seems real – more like a goof on a 1950s horror movie monster than a true threat.
Pic’s cast is a grab-bag ensemble with no real center (toplined Taurean Blacque is killed early on). It eventually finds its emotional core in an affair between crewmen Greg Evigan and Nancy Everhard. A sharp performance by Miguel Ferrer as a punchy, smartmouthed crewmen is diluted when character goes campily berserk.