In the present-day style of the US Navy (and as far as I can tell also the Royal Navy, though I cannot find a suitable link), the definite article is inserted only when giving the type of vessel— [never directly before the vessel's name][1] itself. Thus, the publicity piece entitled “[Nimitz Arrives Home][2]” opens with > More than 3,000 Sailors on board the aircraft carrier USS Nimitz … but subsequent references are bare: > While at sea, Nimitz completed approximately 374 launches and recoveries … > "I am very proud…" said Capt. Jeff Ruth, commanding officer of Nimitz. In vernacular English the article is both prevalent and rather longstanding in use. Early in Shakespeare's *Macbeth*, the first witch [tells a tale][3]: > Her husband's to Aleppo gone, master o' the *Tiger*: Or consider the innumerable examples in *[Purchas His Pilgrimes][4]*, a 1625 book "contayning a history of the world, in sea voyages & lande-travells by Englishmen & others," at least six of which lie in this excerpt: ![the *Eagle*, the *London*, the *Andrew*, the *May-flower*, the *Iacinth*, the *Prim-rose*][5] --- *Why* this became conventional in English is difficult to say. Perhaps it became natural because *the London* would clearly refer to something named after bare *London*— meaning the city— [General Slocum][6] was a disaster, but nothing like the *[General Slocum][7]*. Many large or important physical objects and features idiomatically take the article, and a ship big or important enough to take a name might be expected to do so. But articles are highly idiosyncratic; we weekend on *the Isle of Wight* but on *[Isle Royale][8]*, we sail on the Great Bear Lake though on Lake Ontario, and even climb up *the Matterhorn* yet up *Mont Cervin*— the very same mountain, just known by several names. Proper nouns are particularly twitchy, for not only are names themselves rarely logical (e.g. the people who call themselves *Nederlanders* we call the *Dutch*; the people who call themselves *Deutsche* we call *Germans*), but the entities they represent may have a preferred “house” style that differs from the styles preferred by other substantially similar entities. [Elsewhere][9] I provided the examples of > She is a professor at The Ohio State University. She received her Ph.D. from The George Washington University, and was prepared at The Lawrenceville School. > She is a professor at Kansas State University. She received her Ph.D. from George Mason University, and was prepared at Darrow School. > She is a professor at the University of Arizona. She received her Ph.D. from the College of Charleston, and was prepared at the Milton Hershey School. Related questions include the following: 1. [When to use a definite article in the name of a ship][10] 1. [Using the definite article before a country/state name][11] 2. [Why use “the” for oceans/seas/rivers etc. but not lakes?][12] 3. [Use of definite article before phrases like Heathrow Airport, Hyde Park, Waterloo Station, Edgware Road and Parliament Square][13] 4. [Why 'The' is used?][14] 5. [Should “the” ever be dropped from the beginning of a name/title?][15] 6. [Definite article with proper nouns, titles followed by a common noun][16] 7. [Document names and proper nouns/definite articles][17] 8. [Definite article before schools, colleges, and universities][18] [1]: http://www.navy.mil/submit/view_styleguide.asp?sort=S [2]: http://www.navy.mil/submit/display.asp?story_id=80945 [3]: http://www.shakespeare-navigators.com/macbeth/T13.html [4]: http://books.google.com/books?id=CBJZAAAAcAAJ&pg=PP1#v=onepage&q&f=false [5]: https://i.sstatic.net/tRi9k.jpg [6]: http://www.nps.gov/history/history/online_books/gett/gettysburg_seminars/9/essay3.pdf [7]: http://www.smithsonianmag.com/history/a-spectacle-of-horror-the-burning-of-the-general-slocum-104712974 [8]: http://www.nps.gov/isro/ [9]: https://english.stackexchange.com/questions/93457 [10]: https://english.stackexchange.com/questions/136954 [11]: https://english.stackexchange.com/questions/15484 [12]: https://english.stackexchange.com/questions/72813 [13]: https://english.stackexchange.com/questions/34704 [14]: https://english.stackexchange.com/questions/85601 [15]: https://english.stackexchange.com/questions/72819 [16]: https://english.stackexchange.com/questions/2327 [17]: https://english.stackexchange.com/questions/116997 [18]: https://english.stackexchange.com/questions/10020