October 02, 2022

Marine Detachments

No American armed service has seen more change in its roles than the Marine Corps. When it was founded, its men were soldiers who fought at sea, going aboard almost every American warship. Today, they are soldiers who fight primarily on land, carried across the sea by specialized amphibious ships, and it has been over 20 years since the last Marines came ashore from detached service aboard America's conventional warships, ending the mission that was ultimately the root of the modern concept of the Marine.

Royal Marines go ashore in boats

Soldiers had been going to sea since Antiquity to fight land battles aboard ship. At various points, this had been the main weapon available to warships. For instance, a third of the complement of the ships of the Spanish Armada were Marines, but from that point the the rising importance of naval guns saw this role decrease in importance, while the skills of sailing a ship grew more valuable. But that didn't foreclose the utility of a body of trained troops aboard ships, a practice the British regularized with the founding of the Royal Marines, who specialized in the job, in 1664. They would find their niche in two new roles. First, they were useful for the raids and small amphibious operations that warships were often called upon to perform, being trained as soldiers and also more familiar with the sea than the typical soldier. Second, and perhaps more importantly, they were under similar discipline to the Army and could be trusted to remain loyal to their officers, even if the sailors began to mutiny.

This was vital because the majority of the ship's crew might well have been pressed, and thus neither particularly happy with their situation nor under what we today would consider military discipline. Marines, who were not expected to know how to sail the ship, were, and had long been used as sentries and police aboard ship. To ensure that they could carry out this role, they had berthed and messed separately, and it was a role that increased in importance as the Royal Navy became more mutinous around 1800, although the Marines were far from perfect at it, failing to squelch the Spithead and Nore mutinies in 1797.

Continental Marines go ashore at Nassau, 1776

When Britain's American colonies decided that they'd rather go their own way, they realized that this would require ships, and those ships would, per tradition, require Marines. These Marines would be less concerned with preventing mutiny, as the nascent USN was small enough to crew its ships with volunteers, but their amphibious capabilities and general utility was considered sufficient to bring them along.

US Marines in China during the Boxer Rebellion

This pattern continued to be the bread-and-butter of Marines throughout the 19th century. Stand in neat rows, look fancy, help man the guns and show the sailors how to do it if a landing party was called for. Marines also got the job of guarding naval facilities ashore, which meant that naval commanders had a ready force of organized men when war broke out. The RN also began to use their Marines to paper over some of the odder holes in their personnel system. For complicated reasons, the Navy found itself unable to recruit and retain musicians, and in 1903, the responsibility was given over to the Royal Marines. Traditionally, the Marine Band would man the fire-control spaces in battle, serving as human follow-ups.

The Band of the Royal Marines in the funeral procession for Elizabeth II

But two events around the dawn of the 20th century began to spell doom for the Marine Detachment. First, navies had begun to cook up a new category of ship, the destroyer, and decided that aboard such small vessels, there was neither place nor need for Marines. This made a great deal of sense, as the early destroyers were entirely unsuited for independent cruising, and any landing parties that were needed would undoubtedly come from the numerous cruisers and battleships sitting around. Second, amphibious warfare began to gain steam as a separate discipline, and one it made sense to have the Navy's infantry specialize in, particularly after the debacle at Gallipoli.

Marines at Belleau Wood

The First World War also saw both nations employing their Marines on the Western Front, the British deploying a Marine Brigade as part of the Royal Naval Division, while half of the American 2nd Division was made of Marines, who won honors at places like Belleau Wood. The end result was that, while the Marine detachments aboard large warships endured, with the detachment traditionally manning a turret, the emphasis in both services was clearly on amphibious operations by dedicated, formed units. The British briefly formed a Marine division before turning most of the RM into commando units, which saw service in both Europe and the India/Burma theater, while the USMC eventually grew to six divisions and fought across the Pacific in some of the most brutal battles of the war.

Marines at Guadalcanal

But using Marines this way was transformative, particularly for the USMC. It had been able to operate on a multi-division scale, at the center of its own operations instead of just playing a part alongside the Navy. It had entered the war clearly an adjunct to the USN, but exited it on the road to a status as an almost equal service. Future expeditionary operations would be performed by dedicated Marine units operating from specialized ships, and not by ship's crew and their associated Marines. This alone would probably have been enough to kill off Marine detachments in due course, but their demise was accelerated by another factor. Traditionally, the detachments had been assigned to battleships, cruisers and carriers, and in the aftermath of WWII, battleships were clearly on their way out, with traditional cruisers on the decline as well. Whatever they were called, new warships were being built and manned to destroyer standards, and destroyers had never carried Marines. Instead, the Navy would have to handle its own security, which was done by the expanding Master-at-Arms branch.

The Marine detachment aboard Iowa. They manned the aft starboard 5" turret, visible on the right side of the photo.

But there was one role left on the carriers that would keep the Marine detachments at sea with the USN for a few more decades. Nuclear weapons had begun to go to sea, and the Marine detachments were charged with guarding them, at least on ships that already had Marines. On ships which did not, guard duty was added to the tasks expected of the crew, which tended to make weapons like ASROC unpopular. But on the carriers, and the battleships when they were reactivated, Marines guarded the areas where nuclear weapons might be stored, because the USN doesn't tell anyone who doesn't absolutely need to know when nuclear weapons are or aren't onboard. This brought with it a return to the general internal security role, even a rare return to putting down incipient mutiny as the strains of Vietnam told on the American carriers.

A Marine guard post aboard Midway

But then came the end of the Cold War, and with it the withdrawal of nuclear weapons from ships (except the SSBNs). The Marine detachments lingered on a bit before they were finally withdrawn in 1997. Today, the Marines are almost entirely off doing Marine things and USN handles pretty much all of the various jobs that Marines once did, ranging from ship security to boarding and inspection, with its own personnel, either ship's crew or specialized units like the SEALs. Help is far more likely to come from the Coast Guard than the Marines.

A Royal Marines boarding team

The history of the postwar Marine detachment is less clear in Britain, but today the Royal Marines are, like their American counterparts, primarily focused on amphibious operations as large units. Even the new Queen Elizabeth class carriers have no Marines as a permanent part of the crew, although it appears that the RM is somewhat better-integrated with its parent service, and continues to provide personnel for boarding parties and such on an irregular basis.


  1. October 02, 2022timshatz said...

    Why would the USN be more likely to get help from the Coast Guard than the Marines?

  2. October 02, 2022muddywaters said...

    That's probably referring specifically to boarding teams: nowadays, those are mostly useful against ships that are suspicious but not actively threatening, so it makes sense to assign that job to a police-ish force rather than a military one.

  3. October 02, 2022Mike Kozlowski said...

    ...The Marines also traditionally manned turrets on dreadnaughts - in the RN they often ran one of the main battery turrets and in the USN they usually ran one of the secondaries (WISCONSIN has a USMC insignia on one of her starboard side 5'/38 turrets).

  4. October 02, 2022bean said...


    Because the Marines really don't want to do boarding and such any more. They're quite happy being a small amphibious army, or whatever it is that lets them be independent.


    It's the aft starboard 5"/38 on Iowa. Just forgot to include that, but I have an edit button.

  5. October 06, 2022Alastair McKenzie said...

    REALLY interesting post. I hadn't really thought about the role changes for the Marines, even if I had unconsciously recognised them. Thanks

    (BTW - you can strip this bit out - I wrote earlier this year about Admiral Nelson's disastrous attempt to take Santa Cruz de Tenerife in 1797. It was a classic attempt to over-task the Marines... that, and the fact Nelson was completely out-witted by his opponent. Good at naval strategy, not so good on land. Perhaps the mission should have been commanded by a Marine! https://mechtraveller.com/2022/05/where-nelson-lost-his-arm-at-the-battle-of-santa-cruz-de-tenerife/ )

  6. October 07, 2022cursedcassander@gmail.com said...

    @Alastair McKenzie

    "Fuckups by Famous Commanders" would be an excellent book. I'm adding it to my list of books that need to be written.

  7. October 11, 2022Ian Argent said...

    "Marine Things" is a term in search of a definition right now, at Eighth And Eye Street

    (Weird that it's not Eighth and India, but not incomprehensible)

  8. October 15, 2022Ted said...

    In the article you mentioned that marines were “soldiers” on boats. I’d just like to make a correction, marines aren’t “soldiers”…they’re Marines. Semper Fi

  9. October 15, 2022bean said...

    I'm not trying to insult the Marines there. It's a description of their role, and I can't really change it without being circular.

  10. October 15, 2022Anonymous said...


    I’d just like to make a correction, marines aren’t “soldiers”…they’re Marines.

    Marine ⊊ Soldier.

  11. October 17, 2022Ian Argent said...

    For more fun, the Army calls their personnel "soldiers" as an exclusive term to differentiate between "soldiers, aircrew, sailors, and marines" Last I checked, the blanket term for "persons in military service" was warfighters, but that was a long while back

  12. October 17, 2022bean said...


    That was what Ted was getting at. The standard generic term is "servicemember", with "warfighter" used when they want to sound cool. But soldier is also the term for a person in the military who fights on land.

  13. October 19, 2022Ian Argent said...

    A family member works in a "joint" office where using "soldier" or "marine" improperly will get one Such A Look. And I have close friends who will give out Such A Look as well if mislabeled. I endeavor for strict accuracy here.

  14. October 20, 2022Anonymous said...

    Ian Argent:

    I endeavor for strict accuracy here.

    Strict accuracy is that a marine is every bit as much a soldier as an integer is a real number.

  15. October 21, 2022Ian Argent said...

    I strongly advise not calling a US Marine a Soldier to their face.

Comments from SlateStarCodex:

Leave a comment

All comments are reviewed before being displayed.

Name (required):

E-mail (required, will not be published):


You can use Markdown in comments!

Enter value: Captcha