Complex sentence: The invasion force's convoy escorts close on the submarines position and depth charge the area for over six hours until 1130 causing damage to USS "S-42" and the submarine leaves the area to return to base at Moreton Bay, Brisbane, Australia.
Split into simpler sentences: The invasion force's convoy escorts closed on the submarines position and depth charged the area for over six hours until 1130 causing damage to USS "S-42". The submarine left the area to return to base at Moreton Bay, Brisbane, Australia.