The Battle of Madagascar (5 May – 6 November 1942) was a British campaign to capture the Vichy French-controlled island Madagascar during World War II. The seizure of the island by the British was to deny Madagascar's ports to the Imperial Japanese Navy and to prevent the loss or impairment of the Allied shipping routes to India, Australia and Southeast Asia. It began with Operation Ironclad, (commanded by Major-General Robert Sturges of the Royal Marines) the seizure of the port of Diego-Suarez (now Antsiranana) near the northern tip of the island, on 5 May 1942.
A subsequent campaign to secure the entire island, Operation Stream Line Jane, was opened on 10 September. The Allies broke into the interior, linking up with forces on the coast and secured the island by the end of October. Fighting ceased and an armistice was granted on 6 November. This was the first large-scale operation by the Allies combining sea, land and air forces. The island was placed under Free French control.
0n 27th April 1942: 'A' detachment's submarines I-16, I-18 and I-20 arrive at Penang and are joined by tender NISSHIN that had earlier been converted to carry midget submarines. On the 30th three Japanese "mother" submarines are loaded with a Type A Kō-hyōteki-class midget submarines a type which were also used in the 1941 attack on Pearl Harbor and the 1942 attack on Sydney Harbour.
I-30's plane is to reconnoiter selected points on the East African coast for possible attack and departs in advance. I-10, with Captain Ishizaki embarked, and the A Detachment depart Penang and sortie westward in the Indian Ocean. The I-10's plane is assigned stand-by duty.
The Japanese submarines I-10, I-16, and I-20 arrived three weeks later on 29 May. I-10's reconnaissance plane spotted HMS Ramillies at anchor in Diego-Suarez harbour, but the plane was spotted and Ramillies changed her berth.
The floatplane retrurns to I-10. Captain Ishizaki orders a midget submarine attack for 0230 on 31 May.
I-20 and I-16 launched two midget submarines, one of which managed to enter the harbour.
Lt Akieda Saburo with crew man PO1C Takemoto Masami piloted his craft to a point where he could get a shot in at HMS Ramillies. His first torpedo ran true and impacted just forward of A turret, ripping a 20-30 foot hole in the side of the ship. Although taking on a list and having to flood their magazines the battleship remained afloat, saved by its anti-torpedo bulges.
However the sudden loss of weight caused by the firing one of the torpedoes meant that I-20b was suddenly buoyant and floated to the surface. An Indian lookout on the nearby 6,993-ton oil tanker British Loyalty spotted the conning tower of the submarine. Someone on the tanker managed to get an anti-aircraft gun pointed in the direction of the midget submarine and squeezed off a burst. The volley flew wide and the submarine submerged before he could re-aim
The British escorts then started steaming about dropping depth charges and trying to find the Japanese midget. But the shallow waters frustrated the ASDIC system. Remarkably Lt Saburo stayed in the harbour, and manoeuvred for a killing shot on HMS Ramillies. He lined up his second shot and fired. The torpedo ran true again, however just before impact the British Loyalty steamed in-between the torpedo and the battleship. The tanker had been making a break for open water to avoid being torpedoed, however, this meant that she was in the wrong place at the wrong time for her, but inadvertently saved HMS Ramillies.
The crew of one of the midget submarines, Lieutenant Saburo Akieda and Petty Officer Masami Takemoto, beached their craft (M-20b) at Nosy Antalikely and moved inland towards their pick-up point near Cape Amber.
With both the I-20b's torpedoes gone Lt Saburo set course for the open sea, and the rendezvous point. However they didn't get far as their batteries were depleted. With no power the two Japanese sailors set their scuttling charge and left the boat but the charge failed to detonate. Both men reached the shore, where they approached natives and asked to be ferried to the mainland, which the natives happily helped them with.
Their new plan is to reach a rendezvous point on the northern tip of the island, to be picked up by their mother submarine.
At 1100 on the 1st of June both Japanese sailors approach locals in Anijabe village. They explained they're enemies of the British, but allies of the French and wish to avoid the British forces. They also attempted to purchase food, then leave the village.
One of the locals immediately went and found a patrol of British Royal Marines. The native explained about the visit of a pair of odd looking Chinese men, with pistols and curved swords, it appears the native wanted a payment for the information.
The Marines set off in pursuit of the Japanese and cornered them at Amponkarana Bay. They asked the Japanese to surrender, but they ducked into cover and opened fire, killing one of the Marines. After a short firefight there is a lull, and two shots rang out. Both Japanese sailors had shot themselves instead of risking capture.
Despite a prolonged search the Japanese mother submarines couldn't find any sign of the two midgets they launched. Eventually the subs left the area, apart from I-20 which stayed on station until the 3rd of June. On that day I-20 spent the day on the surface firing flares trying to signal the midget crew. Eventually as dark fell I-20 left the area.
Further reading;
Wikipedia Battle of Madgascar
Combined Fleet Website Imperial Submarines
Overlords Blog East Meets West