Dave Ayling saw former President Barack Obama tee off on the first hole of the Kaneohe Klipper golf course on Dec. 19. And Sandy Shimmon was swimming off of Lanikai on Thursday when she spotted Obama pulling a paddleboard up to the gated home in Lanikai where he’s staying.

But it was the women of the self-proclaimed Windward ReSisters who may have gotten the best up-close meeting with Obama — back home on his first Christmas vacation in Hawaii since leaving office — when they showed up unannounced outside his vacation home on Christmas night, Champagne in hand, to serenade Obama with Christmas carols.

It was not a chance encounter.

“I was visualizing seeing him for two days,” said Windward ReSister Darlene Mandel.

Unlike the eight years Obama spent in the Oval Office, there are no machine gun-mounted boats patrolling the waters off of Kailua this year. And there have been no presidential motorcades to snarl Oahu traffic.

But there’s still plenty of security as Obama’s presence on Oahu over the holidays continues to generate buzz. It’s unclear when Obama arrived or when he will be leaving Oahu.

On Saturday, “My mom saw him hiking Koko Head,” said Kiera Yap, 18, of Kailua, who works as a supervisor at Island Snow on Kailua Road.

During his annual Christmas vacations as president, Obama helped make the original Island Snow a tourist fixture, and several pictures of him still hang on the store’s walls.

A customer Tuesday had just asked what flavors made up Obama’s famous “snowbama” shave ice, said Island Snow founder James Kodama.

(The answer is that the “snowbama” has evolved but usually includes lemon lime or cherry, according to Yap.)

“They take pictures in front of the pictures of President Obama that we have in here,” Kodama said. “Everybody loves him.”

In one picture hanging on the Island Snow walls, Obama wears a simple white T-shirt that reads “Island Snow.” It sells for $25, but the store can’t keep it in stock.

“People see it (Obama’s picture with the shirt) and want it,” said Kekai Hirata, 27, of Waimanalo, another Island Snow supervisor.

Ayling lives in the same Kailuana neighborhood in Kailua where Obama and his family vacationed for eight years while he was in office.

This year Ayling didn’t even know the former first family was in town until he saw the president teeing off at Marine Corps Base Hawaii as Ayling headed for the back nine.

Obama appeared to be part of a foursome, but there were plenty of Secret Service agents and Honolulu police around to draw attention.

“They were all over the place,” Ayling said.

When Obama was president, Ayling and all of his neighbors had to provide Secret Service agents with the names of everyone entering their neighborhood.

“You didn’t even have to lock your door because no one could get in,” Ayling said.

Then on Thursday, Shimmon spotted Obama during her regular ocean swim.

“She was thrilled to see him,” said Shimmon’s husband, Rich, as they stood outside Island Snow on Tuesday.

“It was a big deal for me,” Sandy added.

But it was the women of the Windward ReSisters who captured their meeting on video after they serenaded Obama with a handful of Christmas songs outside his gated entrance.

“We wished we had practiced,” said Windward ReSister Cathy Shun.

Obama didn’t seem to mind.

“No wonder the singing’s so happy,” he says in the video. “I didn’t realize there was Champagne to go with it.”

As the president shook hands with the Windward ReSisters, Brenda Herron may have gotten the best Obama moment so far this holiday season.

“I kissed him on the cheek,” she said. “Hawaiian style.”