Japanese Raiders in The Indian Ocean - Initial Deployment

Initial Deployment

With their heavy armament, they could overpower any smaller combatant or merchant vessel, and their speed enabled them (in combination with their floatplanes) to search large areas of ocean. In service, they were organized as the 24th Special Cruiser Squadron under Rear-Admiral Moriharu Takeda. Hokaku Maru was modified to serve as Admiral Takeda's flagship with space for his staff of four officers and eighteen men.

The 24th Special Cruiser Squadron departed Hiroshima Bay on 15 November 1941 under radio silence and blacked out at night to arrive in a standby position at Jaluit Atoll in the Marshall Islands. They departed Jaluit on 26 November 1941 to patrol the sea lanes between Australia/Samoa/Fiji and the Panama Canal/United States. The operational plan was for one ship to lie-to and drift while performing maintenance, as the other ship carried out a perimeter patrol searching for enemy shipping. The two ships would spend the hours of darkness within visual range; the ships then reversed roles the following day. Following the attack on Pearl Harbor, the search objective changed from avoiding detection to locating enemy commerce.

Following sunset on 12 December 1941, Hokaku Maru stopped the 6,210-ton United States freighter Vincent bound for the Panama Canal from Sydney, Australia at 23 south, 118 west. The old freighter was sunk after taking her crew of 38 aboard the two raiders. The Japanese ships then left the area to avoid any response to Vincent's radio SOS.

Routine searching resumed on 23 December 1941. On 31 December, an Aikoku Maru seaplane found and circled the 3275-ton United States freighter Malama bound for New Zealand from Honolulu with a cargo of Army Air Force trucks and aircraft engines. The seaplane was observed by Malama but was apparently lost to operational problems before returning to Aikoku Maru. The squadron commenced a search for the missing seaplane at 1810 and searched through the moonlit night. Aircraft were launched at 0700 1 January 1942 to expand the search. One of the seaplanes found Malama at 0910, circled at low altitude and ordered the ship to stop with a burst of machine gun fire. Malama began to broadcast distress messages which continued until 1415. Admiral Takeda was 130 miles away, but intercepted the distress calls and ordered the plane to return to be rearmed with bombs. Malama was scuttled by her crew at 25 south, 155 west when the aircraft returned. The squadron left the area after taking the freighter's crew of 38 aboard as prisoners.

Routine searching resumed on 8 January 1942. On 16 and 20 January the squadron intercepted extremely loud radio signals causing them to believe enemy warships were nearby. They successfully evaded detection by Admiral Halsey's Task Force 8. They replenished at Truk on 4 February 1942 and transferred the prisoners to the Oita Bay Naval Air Command on 13 February.

The squadron then entered the Kure Navy Yard where each ship received eight modern 14-cm (5.5-inch) guns to replace the four 15-cm (5.9-inch) guns of Russo-Japanese War vintage installed the previous autumn. More modern seaplanes were embarked when the squadron deployed to the Indian Ocean with the additional duty of resupplying the Japanese submarines operating in the Mozambique Channel. Between 5 June and 13 July 1942, the submarines sank 21 ships, a total of 92,498 tons, the Hokoku Maru and Aikoku Maru added additional ships to that score. With these successes, they had sunk or captured 5 merchant ships within a year, totalling 31,303 tons. They left Singapore on 5 November on their fourth sortie, under the overall command of Captain Imazato Hiroshi.