Write SQL query to solve given problem: What is the longest time for a student from the navy department to be absent from school?. Keep the solution inside sql tag ```sql [SQL-Query] ```
SELECT T1.month FROM longest_absense_from_school AS T1 INNER JOIN enlist AS T2 ON T1.`name` = T2.`name` WHERE T2.organ = 'navy' ORDER BY T1.`month` DESC LIMIT 1