Red Patch The " Red Patch " is a distinguishing device worn by United States Marines with the Military Occupational Specialty ( MOS ) of 0481 ( landing support specialists ) and sometimes 3112 ( traffic management specialists ) , and is worn only on the Marine Corps Combat Utility Uniform . History . The red patch dates back to the early days of World War II during the Battle of Guadalcanal . After the initial assault on the beachhead , follow - on troops came ashore and confusion on the beach led to landing support Marines ( then known as shore party ) and infantry men getting mixed together . Some shore party Marines went inland along with infantry battalions , while some infantrymen were left behind on the beach . It is not known for certain who made the decision , but a device was created in order to distinguish the shore party Marines : a red patch on the trousers and cover ( a patch was not put on the blouse because many Marines did not wear them due to the heat of the South Pacific ) . Around the same time , Naval Shore Parties , now known as Beachmaster Unit One began to wear yellow patches on their uniforms , as they do today . Shore party Marines were either assigned to pioneer battalions or as part of an infantry battalion ’ s shore party . Pioneer battalions consisted of shore party Marines , combat engineers , and heavy equipment operators and were in charge of establishing beach support areas in the Pacific Theater of World War II . Pioneer battalions were sometimes used to relieve infantry battalion s on the front lines and were often involved in heavy fighting in places such as Bloody Ridge on Guadalcanal . One of the more notable shore party Marines was 1st Lt . Alexander Bonnyman Jr . , executive officer of the 2nd Battalion 8th Marines ' Shore Party , who received the Medal Of Honor for his actions during the Battle of Tarawa . Current Usage . The red patch measures on the trousers , worn below the cargo pocket , centered , and on the front of the eight point cover , centered . A patch is supposed to be worn on the front and rear of the Kevlar helmet , but this practice has fallen into disuse . Beginning in the late 1990s , Landing Support Battalions ( which at the time were the only units authorized to wear the red patch ) and their respective Motor Transport Battalions merged to create Transportation Support Battalions ( TSB ) . 1st LSB and 7th MTB merged to create 1st TSB , 2nd LSB and 8th MTB merged to create 2nd TSB , and 3rd LSB and 9th MTB merged to create 3rd TSB . 4th Landing Support Battalion , a reserve unit , remained under the command of 4th Force Service Support Group ( FSSG ) . Subordinate units such as Transportation Support detachments and Landing Support detachments attached to MEU Service Support Groups ( MSSG ) were also authorized to wear the patch . In June 2006 , the three Force Service Support Groups and their respective Transportation Support Battalions were disbanded and fell under the command of various Combat Logistics Battalions ( CLB ) and Combat Logistics Regiments ( CLR ) under the command of the newly created Marine Logistics Groups ( MLG ) . While other Marines dropped the use of the red patch , the patch continues to be worn by Landing Support Platoons or Companies and remains on the uniforms of 0481s and various MOS attached to a landing support company . The red patch also continues to be worn by Marines assigned to the Landing Support Detachments or Transportation Support Detachments assigned to MEU CLBs ( formerly known as MSSGs ) .