“I can’t consider I discovered an actual hermit crab!” exclaims my seven-year-old son, Archer, crouching low on the seashore. He’s smiling on the animal scuttling over the palms of his palms and onto the sand, after which up at my husband, Toby, and me. It’s late afternoon in St. Lucia, and we’ve spent most of our day swimming in Labrelotte Bay at Windjammer Touchdown and scouring close to the rocks for treasures. We’ve turned up loads of coral, mollusks and small fish, however that is the second Archer had been hoping for. The setting solar casts a mild glow throughout his face as he gazes carefully at this small crustacean,…