It has been a rough few days. Steaming up the eastern coast of Japan, Commander Joseph Deleon's guided missile frigate has been tossed around on heavy seas and the younger sailors, back from five months ashore, are feeling seasick. Grounded by high winds, the helicopter pilots are watching movies in the ward room.
The primary mission is hunting submarines. But the USS Gary, like the US Seventh Fleet to which it belongs, is also a showcase of US power in a region fraught with crises -- North Korea, Taiwan, terrorism and piracy.
It is also a region whose security profile is being changed by the rise of China and a major realignment of US forces, and by the prospect of Japan breaking out of its pacifist mind-set and playing a greater defense role.
The fleet's 40-50 ships, 120 aircraft and roughly 20,000 sailors and Marines have an area of operations that spans the Pacific and Indian oceans, 135 million square kilometers from the international dateline to the east coast of Africa. It's a region of the globe that accounts for more than US$220 billion in trade with the US, 98 percent of which moves by sea.
The consequences of a war in these waters are obvious -- global economic meltdown.
With major outposts in Japan, South Korea, Guam and the Diego Garcias in the Indian Ocean, the fleet has a reach and deterrent force that other nations can only envy.
As the Gary makes its way through the Tsugaru Straits between Japan's main island and Hokkaido on its way to exercises with the South Koreans, the flagship of the fleet, the USS Blue Ridge, is 4,830km away making port calls in Kuala Lumpur and Singapore. The centerpiece of it all, the USS Kitty Hawk aircraft carrier, is at the fleet's home port in Yokosuka, just south of Tokyo, undergoing repairs.
But in the Pacific, calm waters can turn rough very fast.
Just a few days' journey away from the Gary is North Korea, openly hostile, claiming nuclear might and technically still at war with South Korea. Then there's Taiwan, a US ally which China claims and threatens to recover by force if necessary.
To the south, the Strait of Malacca, one of the world's most important trade routes, is infested with pirates. Terrorism is rife throughout much of southeast Asia; territorial disputes begin up around the Siberian coast and work their way down to well below the equator.
Taking a short break in his quarters just below the bridge on the Gary, Deleon refuses to single out any specific hotspot as a primary concern.
"We have countries that we are monitoring, that we are aware of," he said.
The rest, he suggests with a look of restraint, is classified.
Some facts speak for themselves, however. With the decline of the once mighty Soviet navy, most of the subs the fleet is tracking are now Chinese.
With its physical size, 1.3 billion people and swelling economy, China casts a lengthening shadow as it establishes itself yet again as a power to be reckoned with.
But where is it going?
Some experts believe that while the Soviet Union was primarily a military rival and Japan an economic one, China could emerge as the first country with the potential to challenge the US on both strategic fronts.
Its economic growth, fanned by robust exports and investment, is expected to be 8.9 percent this year. China is now the world's second-largest consumer and third-largest importer of oil. And this year, its foreign currency reserves reached US$853.7 billion, topping Japan's to become the world's largest.