seaplane

Looks like it's taxiing from the harbor past that biplane. Inboard motors are off & you can see a wake at the bow.

The Kawanishi H8K (二式飛行艇, Nishiki Hikōtei, Type 2 Flying Boat. Commonly called as 二式大型飛行艇 Nishiki Ōgata Hikōtei, 二式大艇 Nishiki Daitei or Nishiki Taitei, Type 2 Large-sized Flying Boat) is an Imperial Japanese Navy flying boat used by the Imperial Japanese Navy Air Service during World War II for maritime patrol duties. The Allied reporting name for the type was "Emily".

The Kawanishi H8K was a large, four-engine aircraft designed for long range and extended endurance on patrols or bombing missions typically flown alone over the ocean. The prototype first flew in January 1941 and H8K1s made their first combat sortie in March 1942. The robust H8K2 "Emily" flying boat was also fitted with powerful defensive armament, which Allied pilots had substantial respect for wherever this aircraft was encountered in the Pacific theater. The H8K was called by Japanese aircraft researcher René Francillon "the most outstanding water-based combat aircraft of the second World War."
https://en.wikipedia.org/wiki/Kawanishi_H8K

The Watanabe E9W was a Japanese submarine-borne reconnaissance seaplane, the first aircraft designed by Watanabe Ironworks.

The aircraft entered service in 1938 with the Imperial Japanese Navy Air Service as the Navy Type 96 Small Reconnaissance Seaplane with the last being delivered in 1940. Although it was in the process of being replaced by the Yokosuka E14Y monoplane, it was still in front line service at the time of the Japanese attack on Pearl Harbor, remaining in service until July 1942, being used to direct their parent submarines onto Chinese ships attempting to pass the Japanese blockade of the South China Sea. The E9W1 was given the reporting name Slim in 1942 by the Allies of World War II.

https://en.wikipedia.org/wiki/Watanabe_E9W