On the eve of her trip to the Southwest, Eva Chen, beauty director at Teen Vogue, sent a tweet: 'Huzzah! I'm officially on vacation!'

Over the next five days, while driving through Arizona, she tweeted more than 120 times, checked-in more than a dozen times on Foursquare and posted more than 30 photos to Instagram.

Upon seeing the Grand Canyon for the first time, she immediately took a picture to share with her more than 32,600 Twitter followers.

'I just want to share the journey with them,' Ms. Chen says of her audience.

In this hyperconnected age, social media is along for the ride -- even on vacation. Unlike with blogs, where a message can be posted to tell readers the blogger will be away, the chatter keeps flowing on Twitter, Facebook and Instagram feeds.

If you stop contributing, you take yourself out of the discussion. At best, followers will tweet at you to ask your whereabouts. At worst, they won't notice you are gone.

Large, corporate brands typically have a team of employees staffing a social-media presence; when one is on vacation, others fill in.

But the most compelling social-media handles, whether a brand, a small business or a person inside a larger organization, usually are the work of one individual, with a uniquepersonality and voice.

Their followers accept no substitutes. And power tweeters don't want to lose traction with followings they have invested time and effort to build.

Douglas Quint, co-founder of Big Gay Ice Cream, a truck and shop in New York City, has more than 37,500 followers for the handle @biggayicecream, many of whom want to find out where they can find the ice cream truck that day. When Mr. Quint took a recent trip to California, he updated the Twitter bio section to say, 'Truck on hiatus 7/16-7/29.'

But he also kept tweeting, to remind people that the store was open for business and to respond to tweets directed at him.

'We need to appear active,' Mr. Quint says. 'We want to appear in people's Twitter feeds once or twice a day.'

For most heavy tweeters, it isn't a burden, or even a work obligation, to stay 'on brand' and connected. It's a choice.

'I don't find it to be an intrusion of my vacation,' says Aliza Licht, senior vice president of global communications for Donna Karan Co., who has amassed more than 413,600 followers on her @DKNY Twitter handle. She also checks work email while on vacation.

'It's not comfortable for me, my personality, to be away,' she says. Her husband and young children are 'accepting' of her social-media connectivity, she says. Sometimes her husband suggests tweets.

Ms. Licht, who has represented the designer brand for almost 14 years, has tweeted from such glamorous places as the Four Seasons in Paris, and from places she considers more 'rustic,' like Atlantic Beach, N.Y., where she has a beach-club cabana.

She takes Donna Karan and DKNY pieces on her trips and tweets while packing -- complete with photos of each ensemble, including a different pair of shoes and handbag for each night, styled like an editorial spread in a magazine.

Her followers appreciate the effort. 'Everyone can go the beach, but not everyone can go to the beach like Aliza,' says Claire Biggs, a New York freelance writer and one of Ms. Licht's enthusiastic followers on Twitter.

So does her boss. 'Her sense of fun and authenticity hugely reflect on our brand and give us an irresistible social presence,' says Patti Cohen, executive vice president of global marketing and communications at Donna Karan.

Melanie Notkin, founder of SavvyAuntie.com Inc., which focuses on women with nieces and nephews, feels a responsibility to engage on social media. People who take the time to share a picture or a story deserve a reply. 'I can't ignore them,' Ms. Notkin says of her more than 19,800 Twitter followers.

As a small-business owner, Ms. Notkin says she doesn't take long vacations. But even on a weekend at the beach, she warns those around her of her need to check her phone.

Not all of her tweets are about aunt-hood, but collectively they paint a picture of life as a single woman in Manhattan. She spent the Fourth of July relaxing in the Hamptons, sharing photos of the pool and ocean view on Twitter and Instagram.

'Many people who follow me enjoy the personal aspects of my life,' Ms. Notkin says. There is a time when she will put the phone down, though. 'I don't drink and tweet,' she says.

Andrew Zimmern, creator and host of the Travel Channel's 'Bizarre Foods with Andrew Zimmern,' says Twitter is his news source. During the Fourth of July holiday week, along with tweets about fireworks and bratwurst, he commented on the death of Ernest Borgnine.

Mr. Zimmern says he will tweet as often as 50 times a day while working, but chimes in less frequently while on vacation. 'It's my own personal enjoyment,' he says of his Twitter feed, which has more than 410,800 followers.

A work trip to Abu Dhabi taught Jamie Beck, a photographer and fashion-photo blogger, to wait until daylight hours in New York to post photos on Instagram. That way, more people see them.

On her recent around-the-world honeymoon -- a safari in South Africa, a night in Sydney, an island getaway in Fiji and a wine tour in Napa -- she saved her posts and shared them later.

At the Londolozi Game Reserve, she used her professional camera to shoot a scene with lions mating, then pulled out her iPhone to grab a few shots to share on social media.

Back at the resort that evening, she selected her favorite pictures and uploaded them to Instagram, where she has more than 50,000 followers.

'I had to share it,' Ms. Beck says. When you aren't around, it's nice when people 'still seeing you creating.' The picture received more than 4,000 likes on Instagram.

Mark Schaefer, author of 'Return on Influence,' a book about marketing and social media, took a two-week 'digital detox' last year on a trip to Europe. Unplugging wasn't easy.

'I had almost a twitch,' Mr. Schaefer says. 'I kept reaching for my pocket.' He tweeted a few times.

Upon returning, he saw his score had dropped on Klout, a site that ranks people based on influence in social media groups. 'If you're not creating a content, then you're not getting a score,' Mr. Schaefer says.

Even so, he finds breaks helpful. He plans trips to places where Internet connections are hard to find or nonexistent. Before leaving, he makes mention of his absence in his bio on Twitter, where he has more than 44,100 followers.

Peter Sagal, host of quiz show 'Wait Wait . . . Don't Tell Me!' on National Public Radio, says Twitter is part of his public persona, and his tweets to more than 60,300 followers require him to be either funny or interesting.

'My family has enough complaints that my mind is elsewhere,' he says. 'If I have something amusing to say in 140 characters, I try to say it to them.'

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