Hearing Yara's question, Zachary promptly reminded her, "Guess how the Soldier Bugs got into the city center. Now that the flying bugs have appeared, it wouldn't be surprising if other types of Bugs Clan show up."
Although Zachary had not seen a Tank Bug crawl out of the cracks, it didn't mean he was unaware of their existence. After all, the initial appearance of the Flame Bug in the movie was quite a climax.
After listening to Zachary's explanation, Yara hesitated for a moment. But considering that there wasn't a single warehouse at the dock that belonged to him, the idea of joining the bustle there faded considerably.
As the dock area became increasingly lively, many of the ships moored in the river began to dock.
Looking at the battle scars left on the decks of the other ships, Zachary praised Yara, "How did you come up with the brilliant idea to modify this ship to be capable of diving?"