If you are looking for a reliable, high-quality "solid piece" of experience, these locations are frequently cited by reviewers as providing the most amazing interactions: Blue Lagoon Island, Bahamas : Highly recommended by Tripadvisor reviewers

A dolphin encounter is rarely just a sighting; it is a sensory experience. The moment a pod of dolphins approaches a vessel or a swimmer, the atmosphere shifts. There is the rhythmic sound of blowholes breaking the surface, the sleek glimmer of grey skin against turquoise water, and the unmistakable feeling of being "observed" by another sentient being. Unlike many land animals that flee from human presence, dolphins often exhibit a playful curiosity, circling swimmers or riding the bow waves of boats in a display of effortless hydrodynamic grace. The "CandidHD" Perspective

The encounter peaks when the pod decides I am boring, but safe. They begin to hunt. The water explodes into a cyclone of silver baitfish. The dolphins cooperate like a single neural network: herding, flashing their white bellies to corral the prey, then diving in unison. The sound of them breathing at the surface— pfffff-tchk! —is a machine gun of life.