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Grande Saline Bay provides temporary anchorage for small vessels while Colombier Bay, to the northwest, has a 4 fathoms patch near mid entrance. In the bight of St. Jean Bay there is a narrow cut through the reef. The north and east sides of the island are fringed, to a short distance from the shore, by a visible coral reef. Reefs are mostly in shallow waters and are clearly visible. The coastal areas abound with beaches and many of these have offshore reefs, some of which are part of a marine reserve.

Some of the offshore reefs of St. Barts are part of what?
a marine reserve