To those who read the author's The Chance of Treasure and The Great Barrier further adventures of the indomitable Brevitts, Mark and , or their Uncle Porty and younger French cousin, Juleen, will be welcomed. Again the setting is the Great Barrier and again the boys perform dangerous and somewhat incredible feats. Skilled equalling divers, trained in coping with the monsters of the deep, loyal to somewhat false at times, the older boys once more achieve the impossible, found treasure hidden in the most unlikely of places, a cabin, tricked two willy and equally determined , and came through safe though not . Even small Jullen was a hero in own right. One can be aceptical about this modern Jules Vern type adventure, but one it with breathless interest and learn many true facts of underwater life off Australia.