Patrona was a military rank of the Ottoman Navy equivalent to a Vice admiral or modern Turkish Tümamiral. The word Patrona was originally Italian as term for the Admiral's galley. The Ottoman Patrona was the second commander of the Ottoman fleet, junior to the Kapudan Pasha (Admiral).
The rank was used since 17th century but abolished in 1855 and replaced by Ferik Amiral.
The Patrona's flag was the red Ottoman flag (including white crescent and star) with a silver cannon on the red ground.
References
Patrona Wikipedia(Text) CC BY-SA