The Hardy Boys / Nancy Drew Mysteries - Season 2 - Eps 20: Death Surf
While windsurfing in Hawaii, Frank tries to rescue a girl named Maryann (Maren Jensen) who disappears and is claimed to be dead. He then begins to become obsessed with finding out what happened to her, but someone, who is also on her trail, is watching him.
About The Hardy Boys / Nancy Drew Mysteries

Title: The Hardy Boys / Nancy Drew Mysteries
First Air Date: 1977-01-30
Last Air Date: 1979-01-14
Status: Ended
Rating: 7/10 (from 26 votes)
Language: EN
Seasons: 3
Total Episodes: 46
Network: ABC
Genres: Mystery, Action & Adventure
Production Companies: Unknown
Synopsis
The Hardy Boys/Nancy Drew Mysteries is a television series which aired for three seasons on ABC. The series starred Parker Stevenson and Shaun Cassidy as amateur sleuth brothers Frank and Joe Hardy, respectively, and Pamela Sue Martin as girl detective Nancy Drew. The Hardy Boys/Nancy Drew Mysteries was unusual in that it often dealt with the characters individually, in an almost anthological style. That is, some episodes featured only the Hardy Boys and others only Nancy Drew.
Cast

Shaun Cassidy
Joe Hardy

Parker Stevenson
Frank Hardy