Secret Harbour

"Secret Harbour" by Stewart Edward White is a mystery that follows a healer of souls that simply goes by the name X. Anaxagoras who convinces a married couple that their life is too idyllic that it's become boring. Soon sure that they're imprisoned by their luxuries and the safety of their routine, they board their yacht and set off for an adventure. What results is a fast-paced adventure of being shipwrecked, marooned, and finding a hidden treasure.