Underwater Defence Group Command (Turkish: Sualtı Savunma Grup Komutanlığı) or Underwater Defence (Turkish: Sualtı Savunma) simply SAS is one of two special operations units of the Turkish Navy, based in the Foça Naval Base near İzmir, on the Aegean coast of Turkey.The missions of the Su Altı Savunma (SAS) include coastal defence operations, such as clearing mines or unexploded torpedoes, and disabling enemy vessels or weapons with underwater operations; as well as counter-terrorism and VIP protection.