Fer-De-Lance is a nice little suspenseful thriller. Snakes, called the Fer-de-Lance ("lance head" in French), is a generic name for vipers and quite poisonous. They have been sneaked on board a research submarine, coincidentally named Fer-de-Lance, by one of the crew to play a trick on the Captain. The snakes escape and bite a few of the personnel. Because of this, the sub loses control and sinks to the bottom of a South Ocean trench and also beneath a landslide. All of this happens within the first 20 minutes and the rest of the movie time is spent in the crew trying to evade the snakes and getting the sub loosened from the rocks.
This movie moves quickly and without much characterization. But that's okay, the characters, though they come from various races, mean nothing to the story. What's important is the race against time to re-surface the sub before it runs out of oxygen for the crew to breathe and before the snakes kill more crew members. What adds to the suspense is the musical score by Dominic Frontiere, which is spot on in catapulting the movie from scene to scene.
The only part of the movie that I'm critical of is the filming of the undersea scuba scenes. They are dark, sometimes out of focus and with debris flying in front of the camera blocking the action. I would think that's done to disguise the fact that the underwater set was small and a large submarine was not really used. But what was being accomplished got across to the viewer, so no harm. The movie is a nice little made-for-tv thriller.