On 20 August, I-8 rendezvoused with the German submarine U-161, commanded by Captain Albrecht Achilles. Two German radio technicians were transferred to I-8, as well as an FuMB 1 "Metox" 600A radar detector, which was installed on I-8's bridge. As I-8 entered the Bay of Biscay on 29 August, the Luftwaffe sent Ju 88 aircraft of KG 40 to provide air cover, she arrived in Brest safely two days later.