Eco-tours. They explicitly don't feed the sharks, they use reusable boxes for lunch and let you refill your bottle with water.
© OpenStreetMap contributors
This is a great way to explore the northern mangrove forest. Head for the leeward side of the island (the west side) for smoother water and to avoid paddling into the wind. Cost for a two-person kayak is BZ$15 per hour for the first hour, then BZ$10 for each additional hour.
An eco-friendly full-day tour on a modern 44ft sailing catamaran with snorkelling guides (typically 1 per 6 guests). The tour includes Hol Chan Marine Reserve, good lunch on board, Shark-Ray Alley, Coral Gardens and rum punch on the way home. It's about BZD20.