4th Naval Armaments Supplement Programme

The 4th Naval Armaments Supplement Program (マル4計画, 第四次海軍軍備充実計画, Maru 4 Keikaku, Dai-Yo-Ji Kaigun Gunbi Jūjitsu Keikaku) was one of the armaments expansion plan of the Imperial Japanese Navy (IJN).

In 1939, the IJN started new naval armaments expansion plan. It extended to 80 warships and 75 Naval Air Groups by 1.6 billion JPY.

• Senshi Sōsho Vol.31, Naval armaments and war preparation (1), "Until November 1941", Asagumo Simbun (Japan), November 1969

• 1st Naval Armaments Supplement Programme (Maru 1 Keikaku, 1931)
• 2nd Naval Armaments Supplement Programme (Maru 2 Keikaku, 1934)
• 3rd Naval Armaments Supplement Programme (Maru 3 Keikaku, 1937)
• Temporal Naval Armaments Supplement Programme (Maru Rin Keikaku, 1940)
• Rapidly Naval Armaments Supplement Programme (Maru Kyū Keikaku, 1941)
• Additional Naval Armaments Supplement Programme (Maru Tui Keikaku, 1941)
• 5th Naval Armaments Supplement Programme (Maru 5 Keikaku, 1941)
• 6th Naval Armaments Supplement Programme (Maru 6 Keikaku, 1942)
• Modified 5th Naval Armaments Supplement Programme (Kai-Maru 5 Keikaku, 1942)
• Wartime Naval Armaments Supplement Programme (Maru Sen Keikaku, 1944)
• マル4計画 (ja)