CREATE TABLE table_name_51 (date_departed VARCHAR, navy VARCHAR, name VARCHAR)

What's the departed date that the HMS Leith of the Royal Navy?
SELECT date_departed FROM table_name_51 WHERE navy = "royal navy" AND name = "hms leith"
SELECT "date_departed" FROM "table_name_51" WHERE "hms leith" = "name" AND "navy" = "royal navy"