Debut: In the premiere episode a man (Chris Robinson) seeking to steal a new invention by Primus' sidekick is thwarted when his two man sub gets trapped when a mining explosion causes an underwater rock fall. The new invention is a robot that allows mining at up to 350 feet below sea level depth. With the aid of the new robot, Primus rescues the would be thief.

A deep sea scientist is stung by a scorpion fish to which he is highly allergic and becomes incapacitated in the depths of the ocean floor.

While training dry land minors to dig on the ocean floor, Primus is warned of a hurricane expected to hit the area of the dive.

The police chase a gang involved in the plutonium black market. Primus replaces one of the gang members, a Navy diver, after the guy is washed away dead on the beach.

Jorge Alquiero hires Primus for a dangerous underwater job. Primus dives after an oceanographer stranded on the ocean floor. But the assignment is hindered by a Benton's plan to steal his sophisticated equipment to look for a treasure.

Primus and Charlie Kingman arc spending 60 days in the undersea habitat Tektite II with three astronauts while they prepare themselves for a life on a manned space laboratory. However, as time elapses, Marshall Grant, one of the astronauts, begins to crack under the stress and strain of the mission and barricades himself in the wet room. Before Primus and Kingman can reach him, he switches off the life-giving supply of oxygen being fed to the habitat, endangering all.