CREATE TABLE table_name_37 (in_service NUMBER, unit VARCHAR2)

What is the highest In service for a vessel with a listed Unit of 12th minesweeper squadron?
SELECT MAX(in_service) FROM table_name_37 WHERE unit = "12th minesweeper squadron"
SELECT MAX("in_service") FROM "table_name_37" WHERE "12th minesweeper squadron" = "unit"