Overview
- JS Chogei (SS 517) was handed over by Mitsubishi Heavy Industries in Kobe and entered Submarine Division 2 at Yokosuka on March 10.
- The 84‑meter boat carries about 70 crew and features the ZQQ‑8 sonar suite, non‑penetrating optronic masts, and lithium‑ion batteries supplied by GS Yuasa.
- From the fourth hull onward the class uses Kawasaki’s 12V25/31 diesel and an updated snorkel to improve power generation and battery charging for the lithium‑ion system.
- The class fields Japan’s Type 18 torpedo and can launch the UGM‑84L Harpoon Block II anti‑ship missile with a range of about 248 km.
- Program momentum continues with the sixth boat Sogei launched in October 2025 for planned commissioning in March 2027 and FY2026 funding set aside for a 10th hull.