Complex sentence: The Royal Canadian Navy and Canadian Army personnel on shore signaled with a light that the escapees were to have used, however the U-boat commander was suspicious, particularly after his hydrophones picked up the sound of the Canadian task group nearby.
Split into simpler sentences: The Royal Canadian Navy and Canadian Army personnel on shore signaled with a light that the escapees were to have used. However the U-boat commander was suspicious, particularly after his hydrophones picked up the sound of the Canadian task group nearby.