Greek Special Operations

Diikisi Ypovrihion Katastrofon (DYK)

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Diikisi Ypovrihion Katastrofon or DYK (Underwater Demolition Command) was formerly known as Monada Ypovrixion Kastrofon (meaning Underwater Destruction Unit). DYK is the Greek Navy’s special warfare unit. DYK is divided into four detachments, or OYKs (Omada Ymourhon Katastophan). DYK has four main missions:

  • Infiltration and sabotage of enemy shipping and bases
  • Reconnaissance and pre-landing beach clearance an designation
  • Ordinance disposal
  • Maritime Counter-Terrorism

Created in 1957, MYK’s initial cadre consisted of two naval officers. The men were sent to Little Creek Amphibious Base near Norfolk, Virginia; where both men undertook the US Navy UDT/R training (the forerunner to today’s BUD/S course). Upon completion of training, the two men returned home and trained an additional dozen men. This group was assigned to the Greek Navy’s amphibious operations command.

In 1959 the unit established its own headquarters and training facilities at Squaramanga Naval Base, but additional training was provided my detachments of USN SEALS and UDT personnel. In 1970 the unit underwent a reorganization and is currently composed of 110 men divided into four operational detachments and a headquarters unit. Each detachment is composed of 25 men and specializes in a certain type of mission:

  • OYK1- unconventional warfare/ intelligence missions
  • OYK2- unconventional warfare/ intelligence missions
  • OYK3- beach recon and hydrographic survey
  • OYK4- conducts EOD operations

    There is also a reserve OYK called OYK5 that would be activated during wartime.

  • Training

    The DYK training course lasts approximately seven months. Training is divided into three phases, with the completion of the course consisting of a five day long “hell week”. Candidates who successfully complete the course go on to attend the Greek Airborne course before being assigned to their unit.

    The following was taken from the DYK’s Official Naval Website (



    • Training staff to become specialist in underwater demolition and diving in accordance with applicable training regulations
    • Taking care for the execution of NAVSPECWAR operational training
    • To provide supervising means and manuals to the underwater demolition teams
    • Keeping staff records for underwater demolition specialists, navy paratroopers and divers.
    • Taking care for the training of underwater demolition specialists in national and overseas training centers (e.g Hellenic unconventional warfare training center – Hellenic military paratroopers school – E.O.D – other NATO SF training)


    1. Basic Underwater Demolition school

    Objective: provide training to personnel in order to become Underwater demolition specialist

    Participating Staff: Officers, petty officers of the Hellenic Navy, Army and Coast Guard.

    Duration: 28 weeks

    Training topics:

    • Endurance in mental and physical fatigue.
    • Martial arts.
    • Hydrographic survey
    • Diving with several types of diving equipment
    • Demolitions
    • Use of standardized explosives
    • Action methods for Unconventional warfare teams.
    • Sabotage
    • Survival

    2. Diving school

    Objective: to make the staff capable of diving up to 20 meters depth in order to support surface crafts and Hellenic Navy units.

    Participating staff: Hellenic Navy, / Armed Forces staff

    Duration: 21 working days

    Training topics:

    • Physical fitness
    • Diving and lifeguard training
    • Contribute in vessels safety

    3. Diving Medicine school

    Objective: to make the diving medical staff capable of diving up to 20 meters depth in order to support diving operations.

    Participating Staff: Hellenic Navy / Armed forces medical staff

    Duration: 21 working days

    Training topics:

    • Physical fitness
    • Diving

    4. Explosive Ordinance Disposal / Standardised Ammunition School

    Objective: To make staff capable to carry out EOD operations in standardized and improvised ammunition.

    Participating staff: Underwater demolition officers and petty officers of the Hellenic Navy.

    Duration: 3 Months

    Training topics:

    • Explosive Ordinance Disposal techniques / procedures


    • Mine-sweeping operations at sea with or without contribution from mine-sweeping vessels
    • Bomb/mine/ standardized ammunition disposal

    5. Seal delivery vehicle operators school

    Objective: to make staff capable of operating SDVs

    Participating staff: Underwater Demolition Officers and Petty Officers.

    Duration: 35 days

    Training topics:

    • Handling and maintenance of underwater delivery vessels
    • Underwater navigation

    6. Unconventional warfare craft school

    Objective: to provide the staff with the necessary knowledge of navigation, nautical skills and operation of unconventional warfare craft.

    Participating Staff: Underwater Demolition Officers and Petty Officers.

    Duration: 15 days

    Training topics:

    • Operation and maintenance of Unconventional Warfare Crafts
    • Piloting
    • Weapon use

    Recent History

    During the Gulf War, two OYKs tasked with enforcing the UN embargo against Irag managed to board and search an astounding 217 ships. They are armed with M-16A2 and MP-11 assault rifles, the MP-5 submachine gun, and the MG-3 7.62 light machine gun.


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