November 12, 2013:
In early November there were media reports that U.S. Navy SEAL commandos had been told to remove a monochrome First Navy Jack (a rattlesnake, superimposed across 13 horizontal alternating red and white stripes with the motto "don't tread on me") patch from their combat uniforms. Some SEALs had been ordered to stop wearing it, apparently because the Tea Party uses the same flag and someone wanted to be politically correct. When contacted the navy quickly denied that such an order had gone out and made it clear that SEALs could continue to wear it.
The "don't tread on me" flag has long stirred strong emotions. The current flag goes back to early 2002 when, to commemorate September 11, 2001 and those who died, all U.S. Navy ships were ordered to replace the normal Union Jack flag (showing fifty white stars on a blue background) with the First Navy Jack. This flag has long been used by the navy for morale building. The flag was first used by Commodore Esek Hopkins in late 1775, as he gathered the continental navy in the Delaware River for operations against British shipping and warships (mostly the former). The First Navy Jack was also used by American privateers (non-navy ships commissioned by the Continental Congress to prey on British merchant shipping). In 2002, sailors were told that for the rest of the War on Terror U.S. Navy ships would fly the First Navy Jack. Soon some SEALs began wearing a First Navy Jack patch on their combat uniforms. This was unofficial, but who was going to argue with the SEALs over something like this?
Before 2002, only one U.S. Navy ship at a time flew the First Navy Jack and that was the oldest ship in the navy. But now it may be a while before only one ship flies the First Navy Jack. The last ship to do that was carrier USS Kitty Hawk (CV 63), which was finally decommissioned in 2009 and ceased to be the oldest ship in the fleet. The Kitty Hawk served for 48 years and 13 days. The ship was the navy's last non-nuclear carrier and, since 1998, the oldest ship in commission. After the Kitty Hawk the USS Enterprise (which entered service seven months after the Kitty Hawk) became the oldest ship.
The First Navy Jack moved around a lot in the 1990s, as the U.S. Navy downsized because the Soviet navy had largely disappeared. This process resulted in some very old ships finally getting retired. The USS Prairie, the last of the pre-war US Navy ships that fought in World War II, was decommissioned on 27, March 1993. The ship, a destroyer tender (a supply and maintenance ship for deployed destroyers), entered service in late 1939. The USS Prairie passed the First Navy Jack on to the USS Orion, a submarine tender commissioned in 1944. But the Orion went out of service later that year and the First Navy Jack rapidly moved from one retiring ship to another until the Kitty Hawk got it in 1998, and held on to it for 11 years.
Technically, the oldest ship in the navy that is still in commission is the sail powered frigate, the USS Constitution. But this is a memorial and museum ship and the "commissioned" status is basically honorary. The two century old Constitution can no longer move under its own power or fight. Eventually older warships that can still fight will again have sole use of the First Navy Jack in their final years of service.