Dolphin Island

From Author Wars - https://authorwars.com/publications/dolphin-island-289723.html

Overview:

Title: Dolphin Island
Author: Arthur C. Clarke
Year: 1963
ISBN-10:
Publisher: Holt, Rinehart and Winston
Price: $3.50
Pages: 186
Binding: Hardcover
Type: Novel
Title Reference: Dolphin Island
Notes:
• "First edition" stated on copyright page. • Green illustrated boards plus dust jacket • Cover art credits on the front flap

The listing in "Spring books from Holt, Rinehart and Wilson", Chi. Tribune 1963-05-12 pJ5, notes "Ages 12 up", $3.50, and "Holt Library Edition, $3.27 net".