Chandler asks Slattery how many ships are in the Greek Navy, Slattery replies that he has no idea. As Greece is a member of NATO the Nathan James would have a list of ships operated by the Hellenic Navy, although with the state of the world there would be no way to know how many are crewed and operational. Under normal conditions the Hellenic Navy has a total of 116 ships, a small number compared to the United States Navy's 490 ships. Though not all are warships, in terms of that the Hellenic Navy has 13 frigates: 9 are Elli-class frigates and 4 are Hydra-class guided missile frigates. The Hellenic Navy operates 10 gunboats of the Osprey and Asheville-class, gunboats are primarily for bombardment of land base targets. They also have 19 missile boats, which are small, fast warships armed with anti-aircraft and anti-ship missiles. The Hellenic Navy also operates 11 submarines of four classes, all are fast attack submarines. The newest and most advanced of those is the Type 214 Papanikolis-class, which is a diesel powered fast attack submarine. While diesel powered submarines do not have the range, speed or submergence time of nuclear powered submarines they have the advantage of being stealthier. Nuclear powered submarines use pumps to constantly circulate coolant throughout the reactor and pumps make noise that can be heard on passive sonar and these pumps cannot be shut off, even if the submarine is running off batter power the reactor still requires constant cooling. However a diesel powered submarine can shut down their main engines and run on auxiliary battery power for several hours if needed, and as a battery system has no moving parts it renders the submarine virtually silent, especially when stopped. A modern high-tech, non-nuclear submarine is best used for coastal defense and can pose a significant risk to a nuclear powered submarine as they can sit on the bottom of the ocean with their engines powered down and become virtually undetectable, while being able to pick up the noise generated by a nuclear powered submarine on passive sonar.
Tregua Island is fictional, used as a literary device in two ways. Tregua means truce in Greek. The writers named it Tregua due to the fact it's where the Nathan James is supposed to meet a plane, kindly made available by friendly Tel Aviv. Also, the word Tregua is used by writer and Auschwitz survivor Primo Levi in his memoir The Truce, about his epic journey (odyssey) from Auschwitz to his home in Italy. This references Homer's Odyssey, too.