United States Marine Corps

===United States Navy===
{{more citations needed|section|date=November 2017}}<!--3 paragraphs have no citations-->
[[File:USS Bonhomme Richard (LHD-6) welldeck.jpg|thumb|alt=color photo of swimming AAVs approaching the well deck of an amphibious assault ship|[[Assault Amphibious Vehicle]]s approaching the [[well deck]] of {{USS|Bonhomme Richard|LHD-6|6}}]]

The Marine Corps's counterpart under the Department of the Navy is the United States Navy. As a result, the Navy and Marine Corps have a close relationship, more so than with other branches of the military. [[White paper]]s and promotional literature have commonly used the phrase "Navy-Marine Corps Team",<ref name="Seapower21">{{Cite journal
|last1= Clark
|first1= Adm. Vern
|author-link= Vern Clark
|title= Sea Power 21
|journal= Proceedings
|volume =130
|issue= October 2002
|page =3005
|publisher= Naval Institute Press
|date=October 2002
|url= http://www.usni.org/proceedings/Articles02/proCNO10.htm
|doi =10.1090/S0002-9939-02-06392-X
|access-date= 28 July 2006
|last2= Hinton
|first2= Don
|archive-url= https://web.archive.org/web/20070303223546/http://www.usni.org/Proceedings/Articles02/PROcno10.htm <!-- Bot retrieved archive --> |archive-date= 3 March 2007|doi-access= free
}}</ref><ref name="EnduringFreedomVid">{{cite video|people = Lt. Col. James Kuhn|title = Enduring Freedom|medium = Film|publisher = Department of the Navy|url = http://www.nuwc.navy.mil/hq/video/enduringfreedom/video.html|date = 2 November 2005|archive-url = https://web.archive.org/web/20060724224601/http://www.nuwc.navy.mil/hq/video/enduringfreedom/video.html|archive-date = 24 July 2006|df = dmy-all}}</ref> or refer to "the Naval Service". Both the [[Chief of Naval Operations]] (CNO) and Commandant of the Marine Corps report directly to the Secretary of the Navy.

Operationally, the Marine Corps provides the [[Fleet Marine Force]]s for service with the Navy's fleets, including the forward-deployed Marine Expeditionary Units embarked aboard Navy amphibious warships. The Corps also contributes some Marine Aviation fixed-wing fighter/attack assets (aircraft squadrons and related aircraft maintenance augmentation units) as part of the Carrier Air Wings deployed aboard aircraft carriers. The [[Marine Corps Security Force Regiment]] provides infantry-based security battalions and Fleet Anti-terrorism Security Team companies to guard and defend high-priority and overseas Navy bases. Security for the Presidential Retreat located aboard the [[Camp David|Naval Support Activity Thurmont, aka ''Camp David'']] is provided by the Marine infantry battalion stationed as part of the garrison aboard Marine Barracks Washington.

Cooperation between the two services includes the training and instruction of some future Marine Corps officers (most are trained and commissioned through Marine Corps OCS), all Marine Corps Naval Aviators (aircraft pilots) and Naval Flight Officers (airborne weapons and sensor system officers), and some Navy and Marine Corps enlisted personnel. The Corps receives a significant portion of its officers from the [[United States Naval Academy]] (USNA) and [[Naval Reserve Officers Training Corps]] (NROTC). USNA and NROTC staff and faculty includes Marine Corps instructors. [[United States Marine Corps Aviation#Aviators and flight officers|Marine Corps aviators and flight officers]] are trained in the [[Naval Air Training Command]] (NATRACOM) and are designated, or ''winged'' as [[United States Naval Aviator|Naval Aviators]] or [[Naval Flight Officer]]s. The Marine Corps provides flight instructors to the Naval Air Training Command as well as [[drill instructor]]s to the [[Officer Candidate School (United States Navy)|Navy's Officer Candidate School]]. Many enlisted marines, particularly those in the aviation maintenance specialties, are trained at Navy technical training centers. The Marine Corps also provides ground combat training support to various Navy field medical (Hospital Corpsmen), Naval Construction Force (Seabee), and Navy Expeditionary Warfare personnel, units, and commands.

Training alongside each other is viewed as critical, as the Navy provides transport, logistical, and combat support to put Marine units into the fight, such as [[Strategic sealift ships|maritime prepositioning ships]] and [[naval gunfire support]]. Most Marine aviation assets ultimately derive from the Navy, with regard to acquisition, funding, and testing, and Navy aircraft carriers typically deploy with a Marine squadron alongside Navy squadrons. Marines do not recruit or train noncombatants such as chaplains or medical/dental personnel; naval personnel fill these roles. Some of these sailors, particularly [[Hospital corpsman|Hospital corpsmen]] and [[Religious program specialist]]s, generally wear Marine uniforms emblazoned with Navy insignia. Conversely, the Marine Corps is responsible for conducting land operations to support naval campaigns, including the seizure of naval bases. Both services operate a network security team in conjunction.

Marines and sailors share many naval traditions, especially terminology and customs. Marine Corps [[Medal of Honor]] recipients wear the Navy variant of this and other awards;<ref name="Lawliss"/> and with few exceptions, the awards and badges of the Navy and Marine Corps are identical. Much of testing for new Marine Corps aircraft is done at [[Naval Air Station Patuxent River]]. The Navy's Blue Angels flight demonstration team is staffed by both Navy and Marine officers and enlisted personnel.<ref name="Lawliss"/>

In 2007, the Marine Corps joined with the Navy and Coast Guard to adopt a new maritime strategy called ''[[A Cooperative Strategy for 21st Century Seapower]]'' that raises the notion of prevention of war to the same [[Philosophy of war|philosophical]] level as the conduct of war.<ref>{{cite web |url=http://www.navy.mil/search/display.asp?story_id=32655 |title=Sea Services Unveil New Maritime Strategy |publisher=Navy News Service |date=17 October 2007 |access-date=3 August 2008 |author=Jim Garamone |archive-url=https://web.archive.org/web/20090305040311/http://www.navy.mil/search/display.asp?story_id=32655 |archive-date=5 March 2009 |url-status=live}}</ref> This new strategy charts a course for the Navy, Coast Guard and Marine Corps to work collectively with each other and international partners to prevent regional crises, human-made or natural, from occurring or reacting quickly should one occur to avoid negative impacts to the United States.