Only five challengers have signed up for the chance to take on software billionaire Larry Ellison’s Oracle Team USA in the 2017 America’s Cup.

Organizers announced Thursday that Emirates Team New Zealand, Italy’s Luna Rossa Challenge, Britain’s Ben Ainslie Racing, Sweden’s Artemis Racing and Team France have passed muster and paid the $1 million first installment of the $2 million entry fee.

That’s an increase of two challengers from the last America’s Cup. But the staggering cost of competing for the oldest trophy in international sports could swamp some competitors, causing Ellison’s vision of a grand regatta with mainstream appeal to fizzle.

An Australian team dropped out earlier this summer, citing the high cost of competing.

There’s still the chance for a late entry, although the viability of such a team would be in question.

The second $1 million installment of the entry fee — which goes to a regatta officials fund — plus a $1 million performance bond is due by Dec. 1.

The 2007 America’s Cup attracted 11 challengers. The 2013 edition attracted only three, and Artemis Racing was set back by a capsize during training that killed British Olympic star Andrew “Bart” Simpson.

Nearly 11 months after the last splash of salt spray from Oracle Team USA’s thrilling victory over Emirates Team New Zealand in the 34th America’s Cup on San Francisco Bay, organizers have yet to pick the venue for 2017 or announce sponsors and a TV deal.

Ellison, the CEO of Oracle Corp., has tasked Russell Coutts, a five-time America’s Cup winner, with planning the next regatta. Coutts has punted San Francisco as the venue, saying it would be too expensive to race there again, and could take the event out of the United States.

Coutts, a New Zealander who has won the America’s Cup for three different countries, is currently deciding between San Diego and Bermuda. Coutts is CEO of Oracle Team USA, director of the America’s Cup Event Authority and is one of three people with Oracle ties on the five-member America’s Cup committee of the Golden Gate Yacht Club, the cup’s trustee.

If Coutts choses Bermuda, a British territory, it would be the first time an American defender has taken the competition out of the United States.

Two syndicates have launched their campaigns with dazzling public events. Ainslie, knighted after winning his fourth Olympic gold medal in 2012, has such star power that Kate Middleton, the Duchess of Cambridge, attended the team’s launch at Greenwich in June.

Ainslie is trying to raise 80 million pounds ($135 million) in his quest to become the first Englishman to hoist the Auld Mug in victory. He has received some government funding and is seeking a new title sponsor after JPMorgan, a New York-based company, recently pulled out. A spokeswoman says the team is happy with the way discussions are going for a new title sponsor.

Coincidentally, Ainslie had a big role in Oracle Team USA’s wild comeback against the Kiwis in September. After Oracle floundered early, in part due to penalties imposed in a cheating scandal, Ainslie replaced American John Kostecki as tactician. Oracle won the final eight races to retain the silver trophy and salvage what had been a star-crossed regatta.

On Tuesday, Artemis Racing announced its return during a ceremony on the Stockholm waterfront. Artemis is owned by oil billionaire Torbjorn Tornqvist.

Luna Rossa Challenge is backed by the Prada fashion house.

While Emirates Team New Zealand is the strongest challenger, it relies on government funding as well as corporate sponsorships. There has been talk that one or more of its sponsors could drop out if Bermuda is the venue. It’s not known who Team France’s sponsors are.

There’s still no word which syndicate will replace Australia’s Hamilton Island Yacht Club as Challenger of Record. Hamilton Island pulled out in July, the second time since Ellison won the America’s Cup in 2010 in a one-off against Alinghi of Switzerland that the Challenger of Record has dropped out due to costs.