Champagne Reef, a few minutes south of Roseau in the Soufrière–Scotts Head Marine Reserve, is the easiest snorkelling in southern Dominica. From the boardwalk at the entry point a short swim takes you over a sloping reef where geothermal vents send columns of fine bubbles up through the water like a slow effervescent shower.
The site is shared by snorkellers and divers. There is a small entrance fee for the marine reserve, and equipment rental on the beach. Sea conditions can be lively from December to March; calmer in the late spring.