COAST GUARD ISLAND – San Francisco Bay was once home port to some of the mightiest warships the world has ever known, but the U.S. Navy's presence now is largely just a memory.

A variety of floating war wagons once docked here – from the hulking Iowa-class battleships to the gigantic Nimitz-class nuclear aircraft carriers, whose appearance on some foreign horizon persuaded warring parties to lay down their arms.

The bay also was home to a massive naval shipyard that could build or repair vessels at a furious rate. Most of those former military wharves, shipyards and dry docks have since been razed and redeveloped.

But before naval historians close the book on San Francisco Bay, they would do well to remember tiny Coast Guard Island, where American warships still operate.

Located deep within the Alameda-Oakland estuary, the man-made island was formed in 1913 by the dredging project that extended the estuary to San Leandro Bay. The first Coast Guard vessels came to the island in 1926.

David Rosen, who serves as historian for the Coast Guard's Pacific Area, said that since the service established a presence on the 67-acre island, some of its most storied leaders and well-known vessels have rotated through the unusual military base.

"As a facility, the island has stood witness to much of the Coast Guard's modern-era development," Rosen said. "Its streets carry the names of leaders who have distinguished themselves in battle or service over the years."

Accessed by a two-lane causeway from the Oakland side of the estuary, the island sports a mixture of historical brick buildings and those of more modern design.

The compact base has all the amenities and features of a small town – a gas station, a general merchandise store, a post office, barber shop and even a Subway sandwich outlet. The island has two large athletic fields, barracks and an Olympic-sized pool.

During World War II the island served as a training facility for both new Coast Guard recruits as well as merchant marine officers who were needed to skipper the famed liberty cargo ships – vital to sustaining the war effort. Following the war and through 1982, the island soldiered on as the Coast Guard's West Coast "boot camp" training center.

Over the years, the place has become the location for some of the service's top brass. It is the headquarters for the Coast Guard's Pacific Area Command and for the 11th Coast Guard District – the latter includes Air Station Sacramento.

The air station was home to the seven-member C-130 Hercules crew who died in a midair collision while conducting a search mission off the coast of San Diego on Oct. 29.

The Coast Guard turboprop is believed to have collided with a Marine Corps helicopter that was on a training mission in the area. The two Marines aboard the helicopter also perished in the accident.

The Coast Guard's Pacific Area is a massive 74 million-square-mile domain ranging from South America, north to the Arctic Circle and west to the Far East. In total, some 27,000 Coast Guard active, reserve and civilian personnel serve in the area.

The smaller District 11 encompasses the states of California, Arizona, Nevada and Utah, and the coastal and offshore waters of Mexico and Central America.

In 2008, the most recent year for which statistics were available, District 11 personnel conducted 2,614 search and rescue missions that saved 503 lives.

The district also conducted 36 counter-narcotics operations resulting in the seizure of 3.5 tons of marijuana and 47 tons of cocaine.

While a variety of Coast Guard units operate there, the island is mostly known for being home to four of the Coast Guard's so-called Hamilton-class High Endurance Cutters – the Sherman, the Morganthau and the Boutwell.

These ships – gleaming white with the traditional orange stripe across their bows – are 378 feet long. Coast Guard cutters these days are about the same size as the U.S. Navy's current fleet of guided missile frigates.