Formally commissioned on 31 March 1934, "Taigei" was soon damaged by a typhoon in what was later called the "Fourth Fleet Incident". Seawater ingression from faulty waterproof doors shorted the electric system, disabling her steering and the waves from the typhoon cracked a number of the welds in her hull. Further repairs at Yokosuka Naval Arsenal were scheduled for early 1936, but were delayed by the February 26 Incident. It was not until September 1938 that "Taigei" was deemed fully operational, and assigned to its design role as flagship of a submarine squadron.