Agent Fletcher refers to the Greek warship as a destroyer. It is actually a frigate, which is smaller and carries less armament than a destroyer.
Chandler states the locks in the Suez canal haven't functioned for a long time but there are no locks in the Suez, the sea flows straight through.
The shot of Chandler standing on the deck of the Nathan James (2:40) is clearly a process shot as the ship is sharply lit from behind while Chandler is more softly lit from his right side.
Chandler wouldn't need to wait for new rank insignia to be made for his uniform, both Slattery and Meylan also carry the rank of Captain and they have plenty of extra uniforms, one of their extra patches could be used. Also in season three it showed Chandler going for days without getting a new name-tag or rank insignia patch, those patches can be made in about five minutes, Navy ships have a special sowing machine that makes new insignia and name patches since uniforms get ruined and need to be replaced fairly often.