Roatán sells one thing above all others: the reef. It is part of the Mesoamerican barrier reef, the second-largest in the world, and on the west of the island the wall starts a few minutes from shore — which is why West End has more dive shops per street than anywhere else in Honduras, and why certification here is among the cheapest in the Caribbean.
The shops below are all in West End or Half Moon Bay at its northern end. What separates them is mostly boat size and pace rather than the sites they visit, since everyone dives the same wall. Prices for an Open Water course cluster tightly; if one quotes far below the others, ask what is not included.
Cruise days change the island. When two ships are in at Coxen Hole and Mahogany Bay the shops fill with passengers on a clock, so a booking made the day before is worth more than it sounds.