Skip bombing Skip bombing was a low - level bombing technique independently invented in several great powers between the World Wars . After Pearl Harbor ( December 1941 ) , it was used prominently against Imperial Japanese Navy warship s and transport s by Major William Benn of the 63rd Squadron , 43rd Bomb Group ( Heavy ) , Fifth Air Force , United States Army Air Forces in the Southwest Pacific area theater during World War II . General George Kenney has been credited with being the first to use skip bombing with the U . S . Air Force . Technique . The bombing aircraft flew at very low altitudes ( ) at speeds from . They would release a " stick " of two to four bomb s , usually or bombs preferably equipped with four - to five - second time delay fuses from the side of the target ship . The bombs would " skip " over the surface of the water in a manner similar to stone skipping and either bounce into the side of the ship and detonate , submerge and explode next to the ship , or bounce over the target and miss . Unlike " Upkeep " or " Highball " , this technique used standard types , although only bombs with a round nose would bounce off the water surface properly . A similar technique was mast - height bombing , in which bombers would approach the target at low altitude , , at about , and then drop down to mast height , at about from the target . They would release their bombs at around , aiming directly at the side of the ship . The two techniques were not mutually exclusive : a bomber could drop two bombs , skipping the first and launching the second at mast height . Practice missions were carried out against the , a liner that had run aground in 1923 . The Battle of the Bismarck Sea would demonstrate that this was the more successful of the two tactics . Aircraft . Various aircraft types were used for skip - bombing attacks , including B - 17 Flying Fortress heavy bomber s , B - 25 Mitchell medium bomber s , and A - 20 Havoc attack bomber s . These were supported by heavily armed Royal Australian Air Force Bristol Beaufighter s , which would suppress Japanese antiaircraft fire with their machine gun s and cannon . The Soviets used lend - leased A - 20 Havocs and P - 40 Tomahawk s as well as Il - 2 Shturmovik s ( also used for air defence suppression ) . Skip bombers were often used by aviation of the Soviet Northern Fleet in combination with torpedo bomber s ( usually the same A - 20 aircraft , skip bomber and torpedo bomber operated in pairs ) . Skip bombers were called " topmachtoviks " ( топмачтовики ) in Russian , because they were flying " at the level of ship mast tops " . Advantages and disadvantages . Skip bombing carried several advantages . Unguided , unpowered bombs are vastly cheaper than torpedoes of equivalent explosive power . Torpedoes take up to several minutes to reach their targets after launch , enough time for an agile ship with an attentive crew to turn and avoid the attack or minimize its damage ; skipped bombs , however , reach their targets in seconds . Skip bombing is additionally carried out at high speeds , increasing bombers ' chances of surviving anti - aircraft fire as aerial torpedoes of the era were dropped at relatively low speeds . The main drawback of skip bombing was that it took a great deal of skill to perfect ; sometimes the bombs would detonate too soon , or in some cases , sink too deep before its delay - fused explosion . History . The first time skip bombing was used in action by U . S . pilots was at the base of Rabaul on New Britain . The United States 5th Army Air Force used B - 25 bombers to attack and destroy Japanese ships . It proved to be a highly effective method and received growing popularity . A notable use of this technique was during the Battle of the Bismarck Sea ( March 2 – 4 , 1943 ) , off the northern coast of New Guinea .