WASHINGTON — White House hopeful Mitt Romney is making the most of a family vacation at their lavish New Hampshire lakefront compound, but there is a question he can't seem to jet-ski away from: who will he pick as his running mate?

The Republican flag bearer has a week of fun and sun, sports and ice cream outings in and around Wolfeboro, a small, 250-year-old New England town where he is set to participate Wednesday in the Independence Day parade, according to his campaign.

It will be the most high-profile of several public showings by Romney and members of his large clan -- about 30 people, including 18 grandchildren -- who have made it an annual tradition to put aside their work lives for one summer week on the shores of Lake Winnipesaukee.

They have been seen trooping into Bailey's Bubble ice cream shop, attending church on Sunday, visiting with friends, lounging on the compound's beach and piling into a speed boat with Romney at the helm.

The family also engages in some good-natured competition in what has been dubbed the "Romney Olympics," a series of sporting events including a bike-swim-run triathlon and a few less-than-traditional activities, like seeing who can hammer the most nails into a board in two minutes.

Photos and video show wife Ann Romney at the controls of a Sea-Doo watercraft, her husband on the back seat, as the couple jet around the lake where the family has vacationed for decades.

But this year is different. Romney is the Republican Party nominee-to-be locked in a tight race against President Barack Obama, and US Secret Service agents are shadowing the candidate's movements.

Romney also has timely campaign decisions to make. Between now and the Republican convention in late August, he needs to zero in on the person he hopes will become his vice president after November's election.

At least two potential picks will be in or near Wolfeboro this week.

Senator Kelly Ayotte campaigned with Romney in her native New Hampshire at the start of his six-state bus tour last month, and she is joining the same July 4 parade as Romney, her office said.

And Senator Rob Portman, a veteran Washington insider from the key swing state of Ohio, will attend a Saturday reception in Concord coordinated by New Hampshire Republicans.

Several vice presidential candidates are still in the mix. Senator Marco Rubio could help Romney win the largest swing state of all, Florida, and neutralize Obama's advantage among Hispanics.

Former Minnesota governor Tim Pawlenty has a personable working-man connection with voters that Romney, a multimillionaire former businessman and investor, lacks.

The choice ultimately will be made by one person.

"This is an election with one voter, Mitt Romney, and he gets to decide who he thinks should be the vice president of the United States," New Jersey Governor Chris Christie told CNBC, hinting he was open to the job.

"I love being governor of New Jersey," he said. "But the fact is, if governor Romney picks up the phone and calls, you have to answer the call and listen at least."

Showing up in person at the candidate's vacation home, reportedly valued at more than $10 million, could allow Romney some face time with the politician he eventually picks as his running mate.

Romney's meticulousness is seen as an asset in this year's vetting, given the events of 2008 when nominee John McCain made what some critics thought was an impulse choice of Sarah Palin, the little-known governor of Alaska, to be his running mate.

The process remains secretive, and the campaign has not disclosed which politicians, if any, may visit Romney this week in Wolfeboro.

"Nobody but a handful of people at the top of the Romney campaign have a clue what's really going on" in terms of the vetting process, University of Virginia professor Larry Sabato, a close watcher of the VP stakes, told MSNBC television on Tuesday.

Romney's vacation comes as both camps present their candidate as the guardian of the American middle class.

Obama, sensitive to how a presidential vacation at an elite retreat might look as he struggles to help turn around the sluggish economy a few months before the election, has opted to skip his annual family trip to Martha's Vineyard.

A senior aide confirmed that Obama and his wife and daughters will not visit the well-heeled isle this year, as they have in the previous three years of his presidency.

After spending a few days at the Camp David retreat, Obama travels Thursday to Ohio to embark on a two-day bus tour.