Chatham Bay is Union Island's finest beach — a wide crescent of pale sand on the western coast, backed by low hills and usually empty of crowds. The bay faces west, which means brilliant sunset light in the late afternoon and calm, sheltered water good for swimming.
Getting there from Clifton requires either a boat taxi around the north of the island (about 15 minutes) or a walk over the ridge (about 45 minutes on a rough track). A few small beach bars operate on the sand, serving grilled fish and rum punches; the owners will often arrange transport back if you ask. The bay is a popular overnight anchorage for yachts, so the evenings can be companionable. Come in the morning during peak season if you want the beach to yourself.