The Royal Navy Beach Commandos and the Royal Marine Commandos, of which No. 48 Commando was one, were very different in role. The Beach Commandos were there to direct the flow of traffic on the beachhead, both ships and landing craft coming to it and vehicles and troops moving off it. The Marine Commandos, meanwhile, were groups of light infantry, used for raiding or frontline combat. There were also RAF Commandos, tasked with rapidly setting up airfields in the wake of an amphibious assault, but I won't discuss them in-depth here.

The RN's early attempts at amphibious landings, such as the abortive attempt at a landing at Dakar in September 1940, indicated a need for greater command and control of the landing. Without control, landings would fall apart; this applied at every scale of the operation. Troops would be misdirected, coordination with the air force and bombarding ships would fail, ships would launch at the wrong time, traffic jams would form on the beach and off it. Part of this problem was solved by the provision of specialised headquarters ships, with all the radios and liaison officers an amphibious commander would need to effectively control his force. This would not solve the issue of traffic direction, though. The solution to this was the Naval Beach Party. These were formed on an ad-hoc basis during the preparation for Operation Ironclad, the 1942 invasion of Madagascar. Here, they would prove a great success, directing traffic and ensuring a smooth flow of troops, vehicles and supplies off the beach. It was decided to formalise them, and form permanent units. However, in naval parlance, a 'party' was an arduous work detail, and there were fears that this might discourage volunteers. Instead, they were given the more exciting name of 'Commandos'.

The Beach Commandos wore the same khaki battledress as the Army did, albeit with naval insignia. They were small units but fitted into a larger beach organisation that included Army and RAF officers and men. Initially, a Beach commando consisted of three sections of two officers and eighteen enlisted men, under the command of a Lieutenant-Commander or Commander. Later reorganisations increased the numbers to three officers and 22 enlisted men per section. A total of 24 Beach Commandos would be formed over the course of the war. They underwent the same training courses as the Marine and Army Commandos, but their job was not to fight. Instead, they would receive specialist training in tasks like signalling, mine clearance and the like. Typically, a small advance party would land with the first assault waves; this would direct the landing craft until the beach was safe for the larger landing craft to bring in heavier equipment. They first saw action at Dieppe, with C & D Commandos suffering heavy casualties. Poor preparation, support and intelligence meant that the landing was a failure, and it was hard for the Beach Commandos to play their role as a result. More successful was their involvement in the landings in the Mediterranean - Torch, Husky, Salerno and Anzio. At Normandy, the advance parties ran into trouble. On Juno, one of the two parties landed successfully, but the landing craft carrying the other was out of position and sank after striking an obstacle, putting the naval men into the water for a long wade ashore. On Sword Beach, three of the eight men in the advance party were killed by German fire, while delays in clearing the exits to the beach meant that the follow-up group struggled to get ashore. After this, the Naval Commandos participated in the seizure of Walcheren island and the crossing of the Rhine, and prepared to head to the Far East for planned invasions of Singapore and Japan.

The Royal Marine Commandos, meanwhile, were fully intended for combat. They were light infantry units, with few heavy weapons and little administrative or logistical 'tail'. They were primarily intended for raiding, and participated in a number of successful raids on both small and large scales. In Normandy, the Commandos were tasked with missions that played to their strengths. These included clearing villages and ports on the flanks of the landings, or pushing ahead to link up with the Airborne inland, before being reinforced by heavier but slower-moving infantry units. 48 Commando was tasked with moving eastward from Juno Beach, to link up with 41 Commando from Sword at Luc-sur-Mer. However, they suffered heavy casualties during the landing at Saint-Aubin. Bad weather had delayed the first waves of Canadian infantry and armour that were supposed to clear the town before 48 Commando landed. Instead, the Commandos landed in the face of a strong German defence they were not fully supported to clear. This resulted in major losses; all of the Commando's five troops were at at most half strength. Two of the troops were reduced to a total of 45 men from a starting total of 130, and the support troop had just one Bren machine gun and one mortar. After fighting through the German defences, they moved to attack the strongpoint at Langrune-Sur-Mer from inland, capturing it on the 7th. Due to the losses incurred in these two operations, they moved into a second-line role on the 8th, helping to bury bodies and mop up any last Germans in Langrune and Saint-Aubin. Reinforcements arrived on the 9th, allowing them to take part in the capture of the radar station at Douvres and re-enter the front line, where they would remain for the remainder of the Normandy Campaign.