The alien's clothing are martial arts gis.
With its "futuristic island" theme, talk of "force fields" and---particularly---Jared Martin's appearance, this is a throwback to the previous year's The Fantastic Journey (1977), Jared Martin's own would-have-been star vehicle. Indeed, Martin starred in this series as "Varian", a man from the future. A party gets lost somewhere in the force field of the Bermuda Triangle, and the cult series chronicled their adventures, as they joined Varian in exploring the island and its "lost worlds" in the hopes of returning to their own time.
Robin Mattson and Anthony Geary who are island inhabitants here both starred in General Hospital together.
Among Robin Mattson's multitude of television roles, she would go on to star in the day time soap opera All My Children, as the infamous character Janet Green, the crow bar killer. She is the arch rival of character Trevor Dillion portrayed by James Kiberd