Japan began the war with a highly competent naval air force designed around some of the best airplanes in the world: the A6M Zero was considered the best carrier aircraft of the beginning of the war, the Mitsubishi G3M bomber was remarkable for its range and speed, and the Kawanishi H8K was the world's best flying boat. The Japanese pilot corps at the beginning of the war were of high caliber as compared to their contemporaries around the world due to intense training and frontline experience in the Sino-Japanese War. The Navy also had a competent land-based tactical bombing force based around the Mitsubishi G3M and G4M bombers, which astonished the world by being the first planes to sink enemy capital ships underway, claiming battleship "Prince of Wales" and the battlecruiser "Repulse".