The Yokosuka E6Y (long designation: Yokosuka Navy Type 91-1 Reconnaissance Seaplane (九一式水上偵察機)) was a Japanese submarine-based reconnaissance seaplane developed at the Yokosuka Naval Air Technical Arsenal for the Imperial Japanese Navy during the 1920s. The prototype first flew as the Yokosho 2-Go (long designation: Yokosuka Arsenal No. 2 Reconnaissance Seaplane (横廠式二号水上偵察機)) in 1929.