As a supply boat .
She avoided combat , she was lost on her first patrol when on 4 August , she was attacked by a Canadian Sunderland flying boat of No. 420 Squadron RCAF , south - east of Iceland .
Although as a supply boat , she avoided combat , she was lost on her first patrol when on 4 August , she was attacked by a Canadian Sunderland flying boat of No. 420 Squadron RCAF , south - east of Iceland .