There were several boarding actions during both world wars.

On the 16th March 1917, the British cruiser Achilles encountered a Norwegian merchant travelling through the North Sea. Believing the ship to be suspicious, Achilles' captain ordered the steamer to accompany Achilles to the inspection ship Dundee. Dundee dispatched a six-man boarding party to search the steamer for contraband goods. The steamer was actually a German raider, the Leopard. Leopard's captain, fearing discovery, detained Dundee's boarding party, and proceeded to engage the two British ships. Leopard fired torpedoes at Dundee, which the latter dodged; a brief gun engagement followed, in which the two British ships heavily outgunned Leopard, sinking her quickly. The boarding action here was minimal, but it did occur. A more extensive boarding action would occur about a month later, on the night of the 20th-21st April 1917. Two half-flotillas of German destroyers launched a raid on Allied shipping in the Dover Strait and a bombardment of Allied ports on either side of the strait. There were a few small encounters between Allied and German ships, and Dover and Calais were bombarded. However, at about 00:45, one half-flotilla encountered two British destroyer leaders, Swift and Broke. The German and British ships ended up at close range in the dark. The British ships turned into the German line, aiming to ram. Swift missed, but fired a torpedo that G.85, sinking her. Broke successfully rammed G.42, and the two ships became entangled. In the confusion, German sailors boarded Broke, and hand-to-hand fighting ensued. Broke's guns poured fire into G.42, but was also engaged heavily by the two remaining German destroyers. Eventually, Broke disentangled herself and limped off, leaving G.42 to sink. Midshipman Donald Gyles, commanding the forward guns, would receive the Distinguished Service Cross for his role in repelling the German boarders.

During WWII, the most well known boarding action is the boarding of the German supply ship Altmark by HMS Cossack. At the start of the war, Altmark had been operating in the South Atlantic. There, she had provided resupply to the commerce raiding cruiser Admiral Graf Spee, and took aboard prisoners from Allied ships captured by Graf Spee. On the 17th December 1939, Graf Spee would be scuttled in Montevideo harbour following the Battle of the River Plate. Altmark's captain, Heinrich Dau, took this as his prompt to return to Germany. His route back, plotted to avoid RN patrols, took his ship around the north of Great Britain, and down the neutral Norwegian coastline. He managed to evade British forces until the 14th February 1940, when Altmark was sighted by aircraft from 220 Squadron RAF. Altmark sought shelter in neutral Norwegian waters, but the British wanted to free the prisoners aboard. On the 16th, Cossack, the nearest British ship, entered the fjord where Altmark was sheltering, and requested that the Norwegians take Altmark to Bergen, with an combined Anglo-Norwegian guard aboard and escorting her. The Norwegians refused this, and so Vian left the fjord to begin preparations for a boarding action. Cossack reentered the fjord following sunset. Philip Vian, captain of Cossack, informed the Norwegian commander that he planned to board Altmark and locate any prisoners himself. The Norwegian was invited to join the boarding party, but he ultimately refused. At 11pm, Dau realised that the ship approaching Altmark was British, not Norwegian. He attempted to escape, training a searchlight on Cossack's bridge to blind her bridge crew. This failed, so Dau attempted first to ram Cossack and then to drive Altmark ashore. Despite this, the British managed to get a boarding party away, led by Lieutenant Commander Turner. Due to the manoeuvring of both ships, Turner had to jump a 6ft gap to board, a leap that some of his boarders nearly didn't make. Thirty-three British seamen and officers got aboard Altmark, and began to seize control of the ship. There was some fighting aboard, with one British sailor, Gunner Smith, and eighteen Germans being wounded, of which seven Germans would die. While Turner successfully captured Altmark's bridge, the ship had considerable sternway on her, and she ran aground. Ten minutes after the boarding, the full contingent of prisoners had been freed, and were evacuated onto Cossack following rumours of scuttling charges having been set aboard Altmark. Cossack left Altmark stranded in Jossingfjord, and returned home to a heroes welcome.

Later in the war, following the Battle of Cape Matapan, British destroyers were deployed to mop up the remaining Italian force after the battleships had crippled a number of Italian cruisers and destroyers. Havock crippled the Italian destroyer Carducci with a torpedo, before sinking her with gunfire. The Australian Stuart sank the Italian Alfieri, again with gunfire. Several other destroyers encountered the Italian heavy cruiser Pola, crippled by an aircraft-dropped torpedo early in the battle. Pola was drifting helplessly, and was essentially unarmed. The British destroyers crowded round her, and Captain Mack, of HMS Jervis, decided to board her, as recounted by Jervis' first lieutenant:

After circling round, Captain Mack said ‘I am going alongside—tell the first lieutenant to prepare wires and fenders starboard side’. ‘A’ gun’s crew armed themselves with cutlasses and prepared to capture by boarding. A perfect approach, and over went a heaving line accompanied by the cry ‘Take this, you b-gg-rs’. Uttering blood-curdling cries, ‘A’ gun’s crew swarmed on board. They came back with a story of chaos. The officers’ cabins had been looted and empty Chianti bottles lay everywhere. Only 256 of a ship’s company of 1,000 remained, and they were huddled on the forecastle; the remainder had already jumped overboard. They filed on board in an orderly fashion followed by the commander and captain. A number showed unmistakable signs of inebriation. After about 20 minutes I was able to report that everybody was on board. Casting off, the Jervis steamed slowly round and illuminated the dead cruiser with her searchlight. Captain Mack then ordered the Nubian to finish her off with a torpedo, after toying with the idea of towing her back to Alexandria, some 500 miles. He reluctantly dismissed it owing to the certainty of heavy air attack next day.

Pola would ultimately be sunk by two torpedoes from Nubian.

A number of submarines would also be boarded and captured, by both sides. Three of these would be used by their opposition. In May 1940, HMS Seal was sent into the Kattegat to lay a minefield. On her return journey, she entered a previously unknown German minefield, and was heavily damaged by a mine explosion. She was forced to the surface, where she was attacked by two German seaplanes. These landed on the sea, and took off the captain, instructing the rest of the crew to wait until a German trawler arrived to capture the submarine. Seal was towed into Kiel, where she would be repaired. She was brought into German service as UB. However, her military utility was limited, as British torpedo tubes were too short to fit German torpedoes. She was used for training, until she was decommissioned in 1941. The British captured two submarines. The Italian Galileo Galilei was captured in the Red Sea in 1940, partly due to her crew being poisoned by leaks from her air conditioning system. She would be brought to Port Said, where she was used as a generating station for British subs, as well as a training boat. The German U-570 was damaged by an aircraft attack in August 1941, with her crew surrendering to the attacking aircraft. She would then be boarded and towed to Iceland by a number of British and Canadian ships. She received some basic repairs there, before being returned to the UK for a more thorough overhaul and examination. Once this was complete, she was brought into service as HMS Graph. Graph made three war patrols, but scored no successes. Ultimately, the lack of spare parts made continued use of her unfeasible, and she was removed from service in 1944.