The crews' caps say "U.S.S. Watertown SSN-696"
In the real world, SSN-696 was the U.S.S. New York City. It was commissioned in 1979 and taken out of service and retired in 1997, a couple of years before this episode first aired.
Harm mentions he has only been on one submarine, the USS Tigershark, a Seawolf-class attack submarine, Chegwidden comments that the USS Watertown is a Los Angeles-class fast attack submarine and he should get used to ducking. Save for one variant, the two submarines are similar in size. The Los Angeles-class nuclear powered fast attack submarine has been in service since 1972, a total of 62 submarines of this class were built between then and 1996, in 2000 they started to be replaced by the new Virginia-class attack submarine. The Lose Angeles-class is 6,818 tons displacement, 362 feet in length, 33 feet wide with a draft of 31 feet, it is armed with two forward and two aft torpedo launchers.
The Seawolf-class was designed in the early 1980's to combat the threat of the Soviet's Typhoon-class ballistic missile submarines, it was designed to carry twice the armament of a Los Angeles-class and has four forward and four aft torpedo launchers that are also capable of firing Tomahawk cruise missiles. At a cost of $3 billion per unit, $3.5 billion for the USS Jimmy Carter, it is the most expensive attack submarine ever built. It is 9,138 tons displacement, 353 feet long, 40 feet wide with a draft of 38 feet. Originally 29 Seawolf-class submarines were ordered, but due to them costing three times the Los Angele-class, and due to the end of the Cold War reducing the threat from Russian submarines only three were actually built. The program was canceled shortly before the third ship was built, it was decided the final Seawolf-class would be specially modified to use for launching remote submersibles and for the deployment and recovery of Navy SEAL teams, as such the final ship of the class, the USS Jimmy Carter (SSN-23), is much larger than her two sister ships, she is 12,139 tons displacement and 452.8 feet long. The planned submarines of the Seawolf-class, and the aging Los Angeles-class fleet, are being replaced by the Virginia-class cruise-missile attack submarine, which cost $2 billion less than the Seawolf and have some major design improvements, the biggest of which are vertical launch tubes on the dorsal section of the hull to allow more rapid and reliable firing of both Tomahawk cruise missiles and Harpoon anti-ship missiles.
The Seawolf-class was designed in the early 1980's to combat the threat of the Soviet's Typhoon-class ballistic missile submarines, it was designed to carry twice the armament of a Los Angeles-class and has four forward and four aft torpedo launchers that are also capable of firing Tomahawk cruise missiles. At a cost of $3 billion per unit, $3.5 billion for the USS Jimmy Carter, it is the most expensive attack submarine ever built. It is 9,138 tons displacement, 353 feet long, 40 feet wide with a draft of 38 feet. Originally 29 Seawolf-class submarines were ordered, but due to them costing three times the Los Angele-class, and due to the end of the Cold War reducing the threat from Russian submarines only three were actually built. The program was canceled shortly before the third ship was built, it was decided the final Seawolf-class would be specially modified to use for launching remote submersibles and for the deployment and recovery of Navy SEAL teams, as such the final ship of the class, the USS Jimmy Carter (SSN-23), is much larger than her two sister ships, she is 12,139 tons displacement and 452.8 feet long. The planned submarines of the Seawolf-class, and the aging Los Angeles-class fleet, are being replaced by the Virginia-class cruise-missile attack submarine, which cost $2 billion less than the Seawolf and have some major design improvements, the biggest of which are vertical launch tubes on the dorsal section of the hull to allow more rapid and reliable firing of both Tomahawk cruise missiles and Harpoon anti-ship missiles.
Legionnaires' disease is an atypical pneumonia caused by types of Legionella bacteria, usually Legionella pneumophila. Symptoms typically involve coughing, shortness of breath, high fever, muscle pain and headaches; some species of Legionella infection can also cause nausea, vomiting and diarrhea. The Legionella bacterium is typically found in fresh water and can contaminate hot water tanks, hot tubs, and large air conditioners. It is spread by breathing in water vapor from a contaminated source, but is rarely transmittable from person to person. Most people exposed to this bacteria do not become infected, typically only people with weak immune systems like the really young and old, or adults who are immune compromised and those with a history of smoking and chronic lung disease are at risk of infection.
Actor Joel Gretsch who played Chief Petty Officer Hodge in this episode of JAG would then appear in 4 episodes of NCIS as NCIS special Agent Stan Burley.