On the night of 29 May "I-30" she sent her aircraft to the harbour of Diego Suarez at the northern tip of Madagascar, which was occupied by the British. The aircraft sighted the battleship at anchor in the bay, along with the destroyers and , corvettes and , troopship "Karanja", hospital ship "Atlantis", tanker "British Loyalty", merchant ship "Llandaff Castle", and an ammunition ship. The next night the Type C submarines "I-16" and "I-20" launched their "Ko-hyoteki" midget submarines about 10 miles from the harbour. At 20:25, one torpedoed and damaged the "Ramillies". The corvettes counter-attacked with depth charges, but at 21:20 the midget from "I-20" torpedoed and sank the "British Loyalty". The "I-16"s midget submarine went missing, presumed sunk, while the "I-20"s beached further along the coast. Its two crewmen were discovered by Royal Marines, and in the ensuing firefight both were killed.