Picture three big, white, handsome cruise ships lined up along San Francisco's Embarcadero.

While you're at it, visualize yourself striding up a gangplank, a happy seagoer in the Bay Area cruise craze.

Now hold that thought. San Francisco is not yet a departure port for cruises in the way that, say, Seattle is.

But that could change with the maritime welcome mat laid out in late February. The opening of San Francisco's new James R. Herman Cruise Terminal promises a classy welcome to cruise passengers and issues an invitation to the cruise industry's new megaships, which this terminal can accommodate.

Just how big? Some behemoths built in recent years are up to 1,200 feet long -- that's almost four football fields -- and can carry 5,000 to 6,000 passengers. Most ships, however, will carry only half that many.

What also has changed is the greeting that awaits visitors. After sailing under the iconic Golden Gate Bridge, passengers will stroll down the gangplank into the new terminal, where floor-to-ceiling windows serve up a live, panoramic postcard of one of the world's most beautiful cities, complete with Coit Tower, Telegraph Hill and the Transamerica Pyramid.

But cruise passengers will have to save their oohs and aahs for early 2014, when the terminal interior at Pier 27 is completed (in the meantime, ships will continue to use the terminal at Pier 35). For the next eight months, the new terminal's 60,000 square-foot empty space is in the hands of its first occupant, America's Cup, which is also the economic force that kick-started the terminal's construction.

This summer, the bay will brighten with speeding sails of the world's fastest ships, 72-foot wing-sail catamarans. America's Cup Park -- akin to an Olympic Village for sailing teams, race officials and media -- will liven the new cruise terminal and several adjacent piers. The races kick off July 4 to Sept. 1 with the Louis Vuitton Cup. The 34th America's Cup finals are Sept. 7-22.

America's Cup organizers pledged as much as $100 million to the city of San Francisco for port and harbor improvements, and the James R. Herman terminal, with its $90 million price tag, got a chunk of that. A 2.5-acre waterfront park, Northeast Wharf Plaza, will be built beside the new terminal, adding waterfront recreation space and a good spot to gawk at a docked cruise ship.

The contract with America's Cup pushed decades of discussion to an action plan, said Peter Dailey, deputy director of maritime for the Port of San Francisco. With the new terminal's capability of accommodating the largest of ships, "We'll stay in step with the industry for the next 50 years," he said.

Bring it, cruise lines

One more thing the James R. Herman Cruise Terminal will accomplish -- actualizing the dream of the former port commissioner for whom the terminal is named. During his lifetime, Herman was a vocal proponent, urging the city to honor its maritime roots and again make San Francisco one of the world's great ports.

Building a new terminal is the first step. The next is to persuade cruise lines that starting a voyage in San Francisco -- not just stopping here -- is a good plan. More departures from home port would be a boon for Bay Area travelers. Monique Moyer, the port's executive director, said cruise lines have been checking in to discuss possibilities.

A major obstacle to San Francisco's becoming a major cruise embarkation port is geography -- the Pacific Ocean doesn't offer numerous destinations in the way the Caribbean does. And unlike East Coast ports -- a week's sail away from Europe -- San Francisco to Asia is a long haul.

Itineraries that currently make port calls in San Francisco follow routes to Alaska; the California Coast; Baja, Mexico; the Pacific Northwest; Victoria and Vancouver, British Columbia; Hawaii; plus a few to Tahiti. Those itineraries, plus a few world cruises and Panama Canal cruises, account for the 66 cruise ships making calls in San Francisco in 2013.

On the plus side, it might not be hard to persuade cruise lines to consider San Francisco as a departure port. The Bay Area is a sophisticated travel region and also home to retiring baby boomers with money to spend. South American itineraries might be popular here, given the elimination of the cost and time of flying to Miami.

Call it home

One company embracing San Francisco's maritime makeover is Princess, which is relocating its Grand Princess here from Fort Lauderdale, Fla. The ship, which arrives here March 16, is a gem. When it was introduced in 1998, it was the largest ship at sea, with 700 balconied cabins, back when 951 feet was really something. Thanks to a multimillion-dollar makeover in 2011, it is now outfitted with more dining and entertainment options, including movies shown poolside, Leaves Tea Lounge and Library, and One5, a late-night nightclub.

Home port status does not mean that Grand Princess will be hanging around. Typically, it will only be in port a short day between voyages, arriving at 7 a.m. to offload passengers, then loading a new set and embarking on its next sail at 4 p.m. Itineraries include Alaska; California Coastal; Wine Country Coastal; and a cruise to Hawaii, Tahiti and the South Pacific.

Like all cruise ships arriving this year, Grand Princess will be ushered into Terminal 35, the old terminal. The terminal, built in 1914, is bleak -- a windowless, unheated steel building that has all the charm of an empty aircraft hangar. Still, Pier 35 has history that dates back to the golden age of cruising, when around-the-world journeys were fashionable for the wealthy.

And it won't be scrapped anytime soon. When more than one ship visits San Francisco at the same time, that extra terminal will come in handy.

Anne Chalfant is a former travel editor for Bay Area News Group and author of the app "Cruise! A Guide for Ships and Trips." ___

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