The Phantom Surfer — Carolyn Keene

With their Starhurst School friends, Jean and Louise Dana spend spring vacation at Horizon, located on the Atlantic coast. The seaside resort town is being restored to its former Victorian-era character. But the restoration project is plagued by thievery and sabotage.

The Danas and their favorite dates, Chris Barton and Ken Scott, are plunged into the thick of the mystery when they witness a lumber theft, discover that signals are being sent from an abandoned lighthouse, and see the nocturnal surfer who time after time mysteriously vanishes before reaching shore.

In between thrills and spills while learning to surf, the lively teenage detectives face many hazards in their attempts to trap the plotters responsible for the sabotaging of the restoration project.