I initially had the same concerns about citing NavSource.org until I did a search for works that have cited the website. I came up with the following through Google Books, listing only those where I could see an actual citation (citations that were specifically for images only are not included):
Holmes, John J.; Balanis, Constantine A. (2006). Exploitation of a Ship's Magnetic Field Signatures. Synthesis Lectures on Computational Electromagnetics, #9. [San Rafael, California]: Morgan & Claypool Publishers. doi:10.2200/s00034ed1v01y200605cem009. ISBN9781598290745. OCLC254572798.
Kennedy, Maxwell Taylor (2008). Danger's Hour: The Story of the USS Bunker Hill and the Kamikaze Pilot who Crippled Her (1st Simon & Schuster hardcover ed.). New York: Simon & Schuster. ISBN9780743260800. OCLC221962047.
Peniston, Bradley (2006). No Higher Honor: Saving the USS Samuel B. Roberts in the Persian Gulf. Annapolis, Maryland: Naval Institute Press. ISBN9781591146612. OCLC63703859.
Scott, Ralph L. (2007). The Wilmington Shipyard: Welding a Fleet for Victory in World War II. Charleston, South Carolina: History Press. ISBN9781596292109. OCLC85822629.
Sewell, Kenneth; Richmond, Clint (2005). Red Star Rogue: The Untold Story of a Soviet Submarine's Nuclear Strike Attempt on the U.S. New York: Simon & Schuster. ISBN9780743261128. OCLC61332564.
Sturma, Michael (2008). The USS Flier: Death and Survival on a World War II Submarine. Lexington: University Press of Kentucky. ISBN9780813124810 0813124816. OCLC181335855. {{cite book}}: Check |isbn= value: length (help)
Tunander, Ola (2004). The Secret War Against Sweden: US and British Submarine Deception in the 1980s. Cass series—naval policy and history, #21. London: Frank Cass,. ISBN9780714653228. OCLC52166050.{{cite book}}: CS1 maint: extra punctuation (link)
Zimmerman, W. Frederick (2008). SSN-23 Jimmy Carter, U.S. Navy Submarine (Seawolf Class). An Arbor, Michigan: Nimble Press. ISBN978-1-934840-30-6.
In addition, these books list navsource.org in their bibliography sections without enumerating what is being cited (does not include mentions in "acknowledgements" or "further reading" sections):
Harvey, Bill (2003). Texas Cemeteries: The Resting Places of Famous, Infamous, and Just Plain Interesting Texans. Clifton and Shirley Caldwell Texas Heritage Series, no. 5. Austin: University of Texas Press. ISBN9780292734654. OCLC50516393.
LaCroix, Hal; Meyer, Jorg (2007). Journey out of Darkness: The Real Story of American Heroes in Hitler's POW Camps: An Oral History. Westport, Connecticut: Praeger Security International. ISBN9780275997441. OCLC123377369.
Page, Charles (2008). Wings of Destiny : Wing Commander Charles Learmonth DFC and Bar, and the Air War in New Guinea. Dural Delivery Centre, New South Wales: Rosenberg. ISBN9781877058646. OCLC187294609.
Rayner, Jonathan (2007). The Naval War Film: Genre, History, National Cinema. Manchester: Manchester University Press. ISBN9780719070983. OCLC71238964.
Thomas, Kathleen (2004). Don't Call Me Rosie: The Women who Welded the LSTs and the Men who Sailed on Them (first ed.). Tigard, Oregon: Thomas/Wright. ISBN9780975485408. OCLC56117036.
There are probably more that are not visible via "Limited Preview" at Google Books. Most appear to be major publishers, including several academic presses. (Obvious vanity press works were excluded.)
