'Pioneer' was a British naval raid on Japanese coastal shipping in the area of Kyaukpyu in the Arakan western coastal area of Japanese-occupied Burma (February 1944).
The raid was carried out by the motor launches ML-438, ML-440, ML-475 and ML-477 of the Indian navy’s 55th Motor Launch Flotilla, but as they approached the harbour the launches found that a rope net was being dragged by ML-475, and this eventually stopped the launch. This impediment was discovered to be part of a wire boom, and considerable difficulty was experienced in clearing the length of wire which had fouled a propeller. The boom actually consisted of 1.25-in (32-mm) wire stretched across the entrance to the harbour from the southern part of Ledaung Kyun across the Reliance Shoal to the shore.
It was therefore decided that it would be impracticable to enter Kyaukpyu, and a gunfire bombardment of Georgina Point was instead carried out without opposition.
While 'Pioneer' was taking place, the 56th Motor Launch Flotilla was carrying out its first operation, namely the gunfire bombardment of Minbyin, half-way along the western coast of Ramree island. ML-412, ML-413, ML-416 and ML-419 took part, and the bombardment resulted in a small explosion and fire ashore. The Japanese apparently returned the fire, as red flashes were seen from the hillside, but no fall of shot was observed, and in due course the force turned back toward its base.
During the night the weather deteriorated and ML-419 lost contact. On the morning of 3 February this launch was attacked by eight Mitsubishi A6M Reisen 'Zero' fighters, which dived on the boat out of the sun at less than 100 ft (30 m). The first attack was with the fighters' machine guns, and thereafter the attacks were made with cannon, machine guns and bombs by the Japanese aircraft attacking in pairs from either side, the first firing its guns and the second dropping bombs. The attack continued for four minutes, and the last two aircraft were hit by the midships 20-mm Oerlikon cannon. Three sticks of light bombs secured near misses and one direct hit on the after end of the bridge wing; the bomb was deflected and passed through the deck and through the side of the launch 1 ft (0.3 m) above the water line before exploding in the water. The launch was damaged, but there were no casualties.