He will now join the crew of a decoy ship: looking like an ordinary fishing schooner, its crew pretending to be civilians, it will actually have a concealed radio to summon the sub chasers as needed.
He is about to embark on a mission to infiltrate a decoy ship: disguising itself as a routine fishing vessel, its crew pretending to be innocent civilians, but equipped with a hidden radio to alert other ships when danger arises.