Humanoids from Atlantis (1992)

Aspiring Film maker Ken Adams has just received financing for his first professional documentary on the city's local lake. What he doesn't know is that the assignment will put him and his partner Julie on a collision course with the last survivor from the long lost aquatic city of Atlantis. Teaming up with a Scientist who has been studying the creature, the team must hunt down the being before he dies due to a lack of radiation. The team eventually track the beast down, and a thrilling chase and fight scene occur showing once and for all who is the dominant species in the epic battle between man and mutant.