The Sharkfighters

In 1943, United States Navy pilot Lt. Commander Ben Staves is ordered to join Operation Shark Chaser at the Naval Research base on the Isle of Pines, just off of Cuba. With its rich proliferation of fish life, the area has long served as a testing ground for the navy in their attempt to develop a successful shark repellent to protect naval personnel in shark-infested waters in the Pacific. Although Ben has little experience with scientific investigation, his exposure to sharks while waiting to be rescued after his plane crashed into the ocean, makes him determined to push for a successful outcome. The research is lead by Lt. Commander Leonard Evans, assisted by chemist Ensign Harold Duncan, and the trials are filmed by Chief "Gordy" Gordon.

Ben reassures Evans that he has not been ordered to replace him on the project, merely to offer assistance to speed up the development of a successful repellent. Although slightly put off by Ben's determination, Evans explains that the team has made numerous discoveries in their study, testing ultrasonic sounds, color clouds, repulsive odors and poison, none of which have had lasting effect in driving away sharks. Ben asks to join the team during one of their trial runs on the ocean. On board the small fishing boat, the men are accompanied by island boy Carlos, who confides in Ben his hopes to move to America some day.

Once Carlos spots several sharks, Evans applies a copper acetate repellent to the water surrounding a large piece of fish bait placed just off the ship's side. While the acetate cloud remains cohesive, the sharks do not take the bait, but within minutes of application, the cloud dissipates and a shark snatches the bait. Duncan suggests the team concentrate their efforts on creating a formula that would remain cohesive longer and Evans agrees. Back at the lab, Ben chafes at the methodical nature of Evans and Duncan's work, but Evans reminds Ben that the nature of the research is not as simple as it appears. Ben suggests that they test several methods at once instead of devoting their sole attention to one procedure. After a few days, Evans takes Ben to Havana to visit his wife Martha, hoping the change of scenery will relax the officer.

That evening at a club, Evans tells Martha that despite Ben's energy and quick ability to learn, his dismissal of scientific methods and determination to make the experiments his own personal battle are troubling. Upon returning to the island, the men continue their research, which is now focused on running numerous trials. Duncan confesses to Ben that after the next results from the trials are forwarded to headquarters, he will request a transfer as he finds the nature of the research wearing and despairs that he is not more involved in the war. Ben makes no response, but that afternoon during another phase of testing out at sea, he notes that the copper acetate cloud has remained consistently cohesive over numerous tests. Enthused, Ben presses Evans to submit the results to the navy immediately, but Evans refuses, reminding Ben that their procedure mandates a required number of tests in order to gauge any differentials.

Moments later, while clowning about the deck, Carlos trips and falls overboard. Terrified by the quick charge made by several sharks, Carlos panics as Evans sprays him with the remaining acetate repellant, which confuses the sharks for a moment, allowing Carlos to swim toward the boat. When a shark then strikes the boy, Ben jumps in to rescue him, but Carlos is too badly injured and dies. At Carlos' funeral a few days later, Ben's commander asks him if he feels the research program is ineffectual, but Ben defends Evans and the study. Upon returning to the lab, however, Ben informs Duncan he will not allow his transfer request and urges Evans to continue trying other repellent substances, such as an earlier suggestion of utilizing octopus ink.

Angered by Ben's apparent cold determination, Evans accuses Ben of too readily accepting questionable test results and points out that the acetate repellent was not ready as proven by its inability to protect Carlos. Ben agrees but insists that the continual use of fish baiting is limited and that to have genuinely conclusive results, they must use human subjects once a new repellent is developed. Evans remains doubtful, but orders Duncan to commence work using octopus ink. Soon after capturing a specimen, Duncan develops a mixture of ink and acetate to keep the ink cohesive as long as possible. Evans insists on viewing Gordy's film of Carlos' death in order to study any unusual details and the men then begin running trials using the new repellent.

Despite Evans' insistence on making twice the number of usual tests, Ben contends that he is the logical choice for human subject because Evans and Duncan are too valuable. On the eve of the human tests, Ben calms an anxious Martha, who is suspicious of her husband's work but unaware of the risk he is assuming. The next day, the researchers are joined by two military marksmen, requested by Ben to provide cover for him during the test. Evans makes a last attempt to convince Ben to wait to have the tests officially approved, but Ben adamantly refuses.

Out at sea, once sharks are sighted, Ben goes into the water and spreads a pack of the repellent about him. For several moments the cloud is effective, but numerous sharks approach and begin circling Ben. Panicked, one of the marksmen fires at the sharks and wounds one, sending the other sharks into a frenzy. Ben begins swimming frantically back toward the boat as Duncan showers him with the repellent. Despite the sharks' agitation, they do not attack Ben and he makes it back into the boat. Elated by the clear success of the repellent, the men head back to shore.