Camie and Rick Bost of Sandpoint, Idaho, are in the throes of their Oahu vacation, but they’ve already started planning their next family trip to Hawaii.

“This tops our list of vacation spots,” said Camie Bost as she watched her 5-year-old son, Cody, interact with a colorful macaw Wednesday at the Hilton Hawaiian Village Waikiki Beach Resort. “There’s just no comparison. We’ve taken trips to Florida, but the water here is so clear and beautiful. We’re already planning next year’s trip.”

The Hawaii Tourism Authority has estimated that travelers like the Bosts will increase the tally of visitors to Hawaii to 8.5 million by year’s end. However, a panel of tourism experts who spoke Thursday during a Hawaii Society of Business Professionals luncheon said maintaining such tourism growth amid increased competition requires continued investment and maintenance by the visitor industry and its public and private partners.

Panelist Rick Egged, president of the Waikiki Improvement Association, said the state’s top tourism district has benefited from $100 million in city infrastructure improvements and $3 billion in private-sector investment. Additionally, Egged said a partnership among the visitor industry, the city and the Institute for Human Services has reduced complaints about homelessness.

“Waikiki reinvestment has made a huge difference. Without that we wouldn’t be generating the returns and tax dollars that we are today,” Egged said.

By upgrading the product, Egged said, Waikiki’s visitor industry has been able to charge more and has had more money to pay for salaries and taxes.

“When the state of Hawaii was in economic doldrums, Waikiki carried the recovery,” Egged said, adding that further sidewalk beautification, beach restoration and building upgrades will add to the destination’s success.

But panelist Michael Troy, field director of online marketing and advertising promotions for Starwood Hotels and Resorts in Hawaii and French Polynesia, cautioned that visitors are increasingly citing the cost of a Hawaii vacation as a barrier.

“Over the last three years, Hawaii has had some of the largest price increases in the marketplace,” Troy said. “With so much competition from destinations in Mexico and the Caribbean that offer all-inclusive packages, we don’t want to price ourselves out of the range of our customers.”

He added that Hawaii hotels also face increased competition from timeshares and even more from privately owned vacation rentals.

“In June of 2013, Hawaii was reported as one of the states with the most Airbnb inventory per capita,” he said. Airbnb “has greater inventory than Starwood and Hilton.”

Panelist Julie Arigo, general manager of the Waikiki Parc Hotel, said she too worries that unregulated vacation rentals reflect poorly on the destination and hurt the bottom line for Hawaii’s hotel industry.

“HTA just published a study that said 22,000 vacation rentals can now be accounted for in this state — representing 25 percent of our total lodging inventory,” she said. “I’m concerned that some units are not being regulated to ensure that they are safe and sanitary for guests. Also, many are not on a level business playing field with hotels.”

Arigo said Hawaii tourism is fragile and that there are many other problems that can affect results.

“We are all affected by tourism, and it is to our advantage to make this the most desirable destination for travel,” Arigo said. “With our visitors paying more, they don’t expect less.”

Among Arigo’s other top concerns are beach erosion, homelessness, human trafficking, off-putting airport conditions, unfavorable exchange rates and the rising cost of a Hawaii vacation amid decreasing visitor satisfaction levels.

“Hawaii’s visitor industry continues to be the largest generator of jobs and the largest source of private capital into the state,” Arigo said. “It’s critical that everyone, not just the businesses that are classified as hospitality, continue to sustain this industry.”