A consideration for Admiral Mikawa after his impressive victory at the battle of Savo Island (August 8-9 1942) was that there were no (zero) replacements afloat or under construction for his heavy cruisers. One might infer that the Imperial Japanese Navy planners did not consider heavy cruisers to be a useful asset, especially in terms of steel and fuel. Accordingly, perhaps losing one or more of his heavy cruisers in exchange for some or many American transports should have been indicated. He was not aware that American carriers would be beyond their attack range. He did have to consider how much ammunition his ships had left and what threats he might face from land-based planes. Before attacking the transports he would have had to fight the cruiser HMAS Australia (8 eight inch guns; at that point almost 20 years old; she did survive the war) and seven destroyers with his seven cruisers and one destroyer. Assuming all the Allied ships were sunk, the question would be how much ammunition remained to attack transports.
Armored cruisers (19th century; veterans of the 1905 Russo-Japanese war)
Asama – completed in 1899; by 1942 a stationary gunnery training ship at Shimonoseki.
Aso – a former Russian cruiser launched in 1908; sunk as a target in 1932.
Azuma – completed in 1900; stricken from the navy list, hulked, and disarmed in 1941. On 18 July 1945, she was badly damaged by US Navy aircraft attacking Yokosuka.
Iwate – completed in 1901; made into a stationary gun platform in the 1940s; bombed by US Navy aircraft attacking Kure on 24 July 1945.
Izumo – completed in 1900 (shown below at anchor in Shanghai 1937); on December 8 1941 at Shanghai sailors from Izumo captured the US river patrolboat USS Wake (PR-3; formerly USS Guam PG-43). Wake was the only US ship that surrendered during WWII. Wake‘s history is a blog article in itself – she was transferred to the pro-Japanese Wang Jingwei regime; recaptured by the US Navy in 1945; transferred to the Nationalist forces in 1946; captured by the Communist forces in 1949 and served in the Chinese Navy for almost 15 years. Izumo assisted in the sinking of British gunboat HMS Peterel also on December 8.
On December 31, 1941, Izumo struck a mine in the Lingayen Gulf off the Philippines. She was towed to Hong Kong for repairs and returned to Japan in late 1943. Izumo was reclassified as a training ship for the Kure Naval District. She struck a mine in Hiroshima Bay April 9, 1945 and was eventually sunk when near-misses by US Navy aircraft sprang the ship’s seams on July 28, 1945.
Kasuga – originally built in Italy for Argentina in 1902, she was ultimately sold to Japan. Kasuga was hulked and disarmed in July 1942 and used as a floating barracks during WWII. On 18 July 1945, she was badly damaged by US Navy aircraft attacking Yokosuka. Kasuga eventually capsized at her mooring.
Nisshin – like Kasuga, she was originally built in Italy for Argentina in 1903, and ultimately sold to Japan. She became a training in 1927 and was sunk as a target ship in 1936. Her wreck was later re-floated and re-used as a target in 1942: towed by the battleship Mutsu, the wreck was shot at by the Yamato.
Tokiwa was completed in 1899 and converted to a minelayer in 1922. She supported several naval campaigns in 1941 and early 1942. Tokiwa was damaged by mines twice in 1945. Additional damage by American aircraft forced Tokiwa’s crew was forced to beach her at the end of the war.
Yakumo was built in 1900 and by the 1920s was used as a training ship. She survived the war and was used as a repatriation vessel during 1946.