Amphibious warfare
The seaplane tender HMS Ark Royal supported the landings under the command of Commander Robert Clark-Hall. Seaplanes were used for aerial reconnaissance, ground support for the troops landing at Anzac Cove and the bombing of fortifications. Ark Royal was augmented by a squadron from the No. 3 Squadron of the Royal Naval Air Service, operating from a nearby island.
Initial landings took place in unmodified rowing boats that were extremely vulnerable to attack from the shore defences. The first purpose-built landing craft were built for the campaign. SS River Clyde, built as a collier, was adapted to be a landing ship for the Landing at Cape Helles. Openings were cut in her steel hull as sally ports from which troops would emerge onto gangways and then to a bridge of smaller boats from the ship to the beach. Boiler plate and sandbags were mounted on her bow, and behind them a battery of 11 machine guns was installed. The machine gun battery was manned by Royal Naval Air Service men. Work began on painting River Clyde's hull sandy yellow as camouflage, but this was incomplete by the time of the landing.

It was soon clear that the Turkish defence was equipped with rapid-fire weapons, which meant that ordinary landing boats were inadequate for the task. In February 1915, orders were placed for the design of purpose built landing craft. A design was created in four days resulting in an order for 200 'X' Lighters with a spoon-shaped bow to take shelving beaches and a drop down frontal ramp.
The first use took place after they had been towed to the Aegean and performed successfully in the 6 August landing at Suvla Bay of IX Corps, commanded by Commander Edward Unwin.
'X' Lighters, known to the soldiers as 'Beetles', carried about 500 men, displaced 135 tons and were based on London barges being 105 feet, 6 inches long, 21 feet wide, and 7 feet, 6 inches deep. The engines mainly ran on heavy oil and ran at a speed of approximately 5 knots. The sides of the ships were bullet proof, and was designed with a ramp on the bow for disembarkation. A plan was devised to land British heavy tanks from pontoons in support of the Third Battle of Ypres, but this was abandoned.

The lessons of the Gallipoli campaign had a significant impact upon the development of amphibious operational planning, and have since been studied by military planners prior to operations such as the Normandy Landings in 1944 and during the Falklands War in 1982. The campaign also influenced US Marine Corps amphibious operations during the Pacific War, and continues to influence US amphibious doctrine.
During the interwar period the campaign "became a focal point for the study of amphibious warfare" in the United Kingdom and United States, because it involved the four types of amphibious operations: the raid, demonstration, assault and withdrawal. Analysis of the campaign before World War II led to a belief among many armed forces that amphibious assaults could not succeed against modern defences. The perception continued until the Normandy Landings in June 1944, despite some successful examples of amphibious operations earlier in the war, such as those in Italy, and at Tarawa and in the Gilbert Islands in the Pacific. Although the negative perception prevailed among Allied planners in the interwar years, the war situation after 1940 meant that such operations had to be considered. However, despite early successes in North Africa and Italy, it was not until Normandy that the belief that opposed landings could not succeed was completely excised.

Interwar developments: One of the first amphibious landings involving armour was conducted by the Irish National Army in 1922, during the Irish Civil War. Landings against Republican rebels at Westport, Fenit and Cork all involved armour cars. The Westport and Fenit landings involved light armoured cars and 18-pounder artillery guns being hoisted off the ships by crane. Heavier armoured cars were used at Cork, resulting in some difficulty. While Irish troops could reach the coast in small boats from naval vessels offshore, the ships had to dock to unload the heavy vehicles and artillery guns. These operations were a major success for the Irish government forces, mainly due to the element of surprise and the use of armoured vehicles and artillery. Government forces were able to capture all the major towns and cities in southern Ireland.
The Alhucemas landing on 8 September 1925, performed by a Spanish-French coalition against rebel Berber tribesmen in the north of Morocco, was an amphibious landing where tanks were used for the first time and massive aerial and naval gunfire support was employed by the landing forces, directed by spotting personnel with communication devices.
Floating depots were organized with medical, water, ammunition and food supplies, to be dispatched ashore when needed. The barges used in this landing were the surviving "K" boats from Gallipoli, upgraded in Spanish shipyards.
In 1938, Japanese forces attacked Chinese defenders over the Yangtze River at the Battle of Wuhan. Soon, the Japanese would later further improve its techniques upon seaborne assaults by the Second Sino-Japanese War. By World War II, marines such as the Special Naval Landing Force used amphibious landings to attack and sweep across territories in South East Asia. Their technique of surprise landings with naval support inspired the British and American landings in World War II such as D-Day and the Pacific Campaign.

Britain: During the inter-war period, the combination of the negative experience at Gallipoli and economic stringency contributed to the delay in procuring equipment and adopting a universal doctrine for amphibious operations in the Royal Navy.
The costly failure of the Gallipoli campaign coupled with the emerging potential of airpower satisfied many in naval and military circles that the age of amphibious operations had come to a close. Still, throughout the 1920s and 1930s, animated discussion in Staff Colleges in Britain and the Indian Army Staff College at Quetta surrounded the strategic potential of the Dardanelles campaign compared with the strategic stalemate of the Western Front. The economic austerity of the worldwide economic depression and the government's adoption of the Ten Year Rule assured that such theoretical talk would not result in the procurement of any large scale equipment.
Despite this outlook, the British produced the Motor Landing Craft in 1920, based on their experience with the early 'Beetle' armoured transport. The craft could put a medium tank directly onto a beach. From 1924, it was used with landing boats in annual exercises in amphibious landings. It was later called Landing Craft, Mechanized (LCM) and was the predecessor of all Allied landing craft mechanised (LCM).
The Army and Royal Navy formed a landing craft committee to "recommend... the design of landing craft". A prototype motor landing craft, designed by J. Samuel White of Cowes, was built and first sailed in 1926. It weighed 16 tons and had a box-like appearance, having a square bow and stern. To prevent fouling of the propellers in a craft destined to spend time in surf and possibly be beached, a crude waterjet propulsion system was devised by White's designers. A Hotchkiss petrol engine drove a centrifugal pump which produced a jet of water, pushing the craft ahead or astern, and steering it, according to how the jet was directed. Speed was 5–6 knots and its beaching capacity was good. By 1930, three MLC were operated by the Royal Navy.

For a short journey, from shore to shore, the cargo could be rolled or carried into the boat over its ramp. On longer journeys, ship to shore, a derrick would lower the MLC into the sea from the transporting vessel. The derrick would then lower the vehicle or cargo load. Upon touching down on shore, soldiers or vehicles exited by the bow ramp.
Although there was much official apathy toward amphibious operations, this began to change in the late 1930s. The Royal Naval Staff College at Greenwich, drafted a document detailing combined operations requirements and submitted it to the Chiefs of Staff in 1936. The document recommended the establishment of an inter-service 'Training and Development Centre', with a permanent force of Royal Marines attached to it. Its functions were to "train in all methods for the seizure of defended beaches; develop the materiel necessary for such methods, with special regard to protection of troops, speed of landing, and the attainment of surprise; and develop methods and materiel for the destruction or neutralization of enemy defenses, including bombardment and aircraft co-operation.
The Inter-Service Training and Development Centre was established at Fort Cumberland, near Portsmouth in 1938, and brought together representatives from the Royal Navy, Army, and Royal Air Force convened with the portfolio of developing methods and equipment to use in Combined Operations.
The Centre examined certain specific problems, including craft for landing tanks, beach organisation, floating piers, headquarters ships, amphibian tanks, underwater obstacles, the landing of water and petrol and the use of small craft in amphibious raids By the end of 1939 the ISTDC had codified a policy for landings, and defended it at Staff College discussions. Operational experience during the Second World War introduced modifications to this landing policy, but it was essentially the policy used in the Torch and Husky landings four years later.