C336 Wave after Wave

"Hurry up and confirm what ship it is!" Xiao En shouted loudly, "Is it a warship or a civilian ship!?"

"I... "This …" The sonar officer was stuttering.

"What's wrong?" Xiao En asked.

"I can't tell what ship it is …" The sonar officer picked up a headset and said helplessly.

"What?" Xiao En walked over, puzzled.

"Engine noise is very loud... It should be an old type of ship