"They're like family, basically," Pritchett said of the eclipse enthusiasts. "It's something that they're very much interested in. Once it gets in their blood, it's there."
For tours with Ring of Fire or Spears, participants pay about $3,600 to $3,800 for a 10-day package (not including airfare). But other travel firms offer more focused experiences.
Cox and Kings, a travel company in India, was offering a three-hour flight on board a Boeing 727-700 aircraft that would follow the path of the eclipse at 41,000 feet. Passengers were to board a plane in New Delhi before dawn, then fly southeast to Gaya and back. Depending on where they are on the plane, seats cost from about $600 to $1,600.
Since the eclipse is taking place during the monsoon season, the travel company says this is a "virtual guarantee" of seeing an uninterrupted view of the eclipse.
Other companies offered views from the water. TravelQuest International of Prescott, Ariz., teamed with Sky & Telescope magazine for a two-week cruise in the South Pacific. Starting at $6,995 per room, the cruise promised about three minutes and 26 seconds of totality from the Northern Cook Islands.
Because of its location just east of the International Date Line, they would have seen the eclipse tonight at sunset local time.
According to local reports, the event is giving a boost to tourism in the area. Special eclipse breakfast deals sold out in Shanghai hotels, according to ChannelNewsAsia.com. And online vendors saw sales of special solar glasses climb. The glasses allow skywatchers not in the path of the moon's shadow to look directly at the sun.
Although there's a growing audience for solar eclipse tours, David Swanson, a contributing editor for National Geographic Traveler magazine, said interest is mitigated by the fact that some eclipses happen in hard-to-reach areas or places with poor weather conditions.
This month's eclipse is easily accessible but cloud cover was expected to block some views of the corona, he said. But if the weather had cooperated, tens of millions of people across Asia could have witnessed the eclipse.
And, he said, the experience is unparalleled.
"I don't know anyone who has seen a successful eclipse and wasn't pretty much blown away and wanted to see another one," Swanson said.
He saw his first in Antigua in 1998 and has seen two more since then.
As the moment of totality approaches, he said the sky gradually darkens and starts to take on something similar to the light at twilight.
"All of a sudden, the color starts to drain away. ... The breeze stops. Birds stop chirping. It's a very unusual experience," he said. "It's like being transported to another planet for a few minutes."