The exercise brings together 31 surface ships, 1 submarine, 3 maritime patrol aircraft and other air assets as well as personnel, from Belgium, France, Greece, Italy, Netherlands, Spain, and the United States. Dynamic Mariner-20 (DYMR20) is led by the NATO Maritime Command and involves Standing NATO Maritime Group Two (SNMG2) and Standing NATO Mine Countermeasures Group Two (SNMCMG2), two of NATO’s Standing Forces on active duty that contribute to the Alliance’s collective defence on a permanent basis.

The U.S. participation in this exercise demonstrates the U.S. commitment to working closely with NATO allies and partners to enhance maritime security and stability, readiness, and naval capability. 

The Standing NATO Maritime Group 2 (SNMG2) is a North Atlantic Treaty Organisation (NATO) standing maritime immediate reaction force. SNMG2 consists of four to six destroyers and frigates. Its role is to provide NATO with an immediate operational response capability. The SNMG2 is under the command of Rear Admiral Manuel Aguirre Aldereguía from the Spanish Navy. The SNMG2 ships as of 20 September 2020 consist of F-101 Álvaro de Bazán class frigate of the Spanish Navy, HS POLEMISTIS P-61 – HSY-55 Gunboat Class from Hellenic Navy, PGFG Mikonios 22 – La Combattante III Class fast attack craft from Hellenic Navy and TCG KARABURUN P-1201 Tuzla Class Patrol Boat of Turkish Navy.

The Standing NATO Mine Countermeasures Group Two (SNMCMG2) is a North Atlantic Treaty Organisation (NATO) standing mine countermeasures Immediate Reaction Force. Its role is to provide NATO with an immediate operational response capability. The SNMCMG2 is under the command of Captain Dimitrios Katsouras from the Hellenic Navy. The flagship of the SNMCMG2 is the HS ALIAKMON A470 – 701C class (Lüneburg) replenishment ship.