The Samana peninsula arches up from the northeast coast of the Dominican Republic on the island of Hispaniola, encircling a bay that is a consensus pick as one of the world’s most beautiful. The town, actually named Santa Barbara de Samana, is on the bay side, and is blessed with all that Caribbean daydreams are made of: sugary white beaches, jewel-blue seas, feathery coco palms and a laid-back a…