CREATE TABLE table_46311 ("from" TEXT, "aircraft" TEXT, "carrier" TEXT, "air wing" TEXT, "tail code" TEXT, "area" TEXT)

Which carrier was deployed on 18 July 1968?
SELECT "carrier" FROM table_46311 WHERE "from" = '18 july 1968'
SELECT "carrier" FROM "table_46311" WHERE "from" = '18 july 1968'