<Li> Bank reef--linear or semicircular shaped - outline, larger than a patch reef </Li> <Li> Ribbon reef--long, narrow, possibly winding reef, usually associated with an atoll lagoon </Li> <Li> Table reef--isolated reef, approaching an atoll type, but without a lagoon </Li> <Li> Habili--reef specific to the Red Sea; does not reach the surface near enough to cause visible surf; may be a hazard to ships (from the Arabic for "unborn") </Li>

Which feature is characteristic of healthy coral reefs