Gidget translates 'Kahuna' as the 'wailing ultimate'; Mr. Lawrence asks whether the Kahuna is a High Priest. They both ascribe to the Kahuna, played by Martin Milner, attributes that fit the meaning of the term, which from the Hawaiian can mean 'expert', 'priest', or simply 'top dog'.
While this is their only appearance together in front of a camera, Sally Field and Martin Milner started their acting careers at about the same age: 15 or 16 years old.
Martin Milner plays a character who is supposed to be quite older than Gidget. He was, in fact, nearly 15 years older than Sally Field.
Martin Milner started his acting career at age 15-going-on-16 in Life with Father (1947). By the time he appears in this series, he has been in the business nearly 18 years, usually, as here, in supporting roles. A starring role for him was just a few years away, when he took on the part of Officer Pete Malloy in the long-running TV series Adam-12 (1968), a role for which he is perhaps best known.