PORTLAND – It used to be the coolest, hippest summer job. Getting paid while getting a tan. Endless summers. Healthy, fit hunks and babes, a la “Baywatch.”

Today, many of the nation’s beaches and pools can’t hire enough lifeguards, and those that are fully staffed are paying top dollar.

With opening day fast approaching, nearly 30 percent of the 52 lifeguard jobs at Maine state parks remain unfilled.

“This is the third year that we’ve had a real difficult time,” said Gloria Allen, Maine’s lifeguard coordinator.

New York City expects to fall about 150 lifeguards shy of its hiring goal of 1,100 this summer. Elsewhere, there is a scramble to fill those jobs before the beaches become crowded with summer sunbathers.

The reasons for the shortage over the past couple of years include low pay and the time commitment necessary to get certified, especially in places with short summers, like Maine.

But Lanee Barnes, a 14-year veteran, fears there’s another problem: Lifeguarding may not be as cool as it used to be.

“People don’t look at lifeguarding as a glamorous job. They look at it as someone who isn’t ambitious and wants to fool around all summer. That’s not the case at all,” said Barnes, 31, who works at Reid State Park in Georgetown.

Lifeguarding is serious business.

Barnes made two saves last summer at Reid, a park with beaches and dunes 43 miles from Portland, and she sometimes gets headaches from focusing intently on children romping in the surf for hours on end.

“It’s an intense level of concentration,” she said. “It’s not like working at a computer where you can turn it off. You can’t turn this off. You turn this off and something bad is going to happen.”

Not even full benefits, including dental coverage and a retirement plan, have been enough to lure applicants in Maine, where pay starts at $8.57 an hour.

The requirements of the job are partly to blame. It costs $100 to $300 to get certified as a lifeguard in Maine, including training in cardiopulmonary resuscitation and first aid.

To work on a beach in Maine, lifeguards must be able to swim 500 yards in 10 minutes and run 11/2 miles in 12 minutes.

And the demands are growing. In Virginia Beach, Va., lifeguards will be equipped this summer for the first time with portable defibrillators to help shock people out of cardiac arrest.

“A lot of people, quite frankly, can do a lot of other things and put less work into it than being an ocean lifeguard,” said Kent Hinnant, chief of operations for the Virginia Beach Lifesaving Service.

Some beaches, especially those open year round in places such as Southern California, offer starting pay of more than $13 an hour, and some pay veterans up to $20 an hour. Those places are unlikely to have hiring problems, experts say.

Pay is rising elsewhere, as well. In Glynn County, Ga., it has gone up from $7 to $10 an hour this year, and pay rose from $5.15 to $7.50 an hour over two years in Marquette, Mich. Ohio state parks have raised pay from $5.50 to $8.15 an hour.

The shortage has created a rift between those who say communities must meet the need and those who advocate a new approach. Tom Griffiths, director of aquatics at Pennsylvania State University and author of the book, “Better Beaches,” is among the latter.

Griffiths favors hiring lifeguards for the busiest swimming areas, but scaling back at less-visited places.

He believes some places would be better off with visiting beach patrols, whose members would educate beach-goers about the dangers of the surf, than with young and inexperienced full-time lifeguards.

Some are listening.

In Indiana, there are lifeguards at only two of 21 state parks with beaches. The decision to scale back lifeguards coincided with a shortage of applicants, but that wasn’t the primary reason for the change, said Russ Grunden, spokesman for the Indiana Department of Natural Resources.

There was a feeling that parents were leaving children unsupervised and that the lifeguards were becoming baby sitters. With the change, parents are now keeping a closer eye on their children, Grunden said.

The approach also has taken hold in Port Clinton, Ohio, a tourist town along Lake Erie. The community cleaned up and widened its main public beach this year, but it hasn’t hired any lifeguards for the summer.

Instead, the town has posted signs warning of no lifeguards, as it did the last two summers.

In New Jersey, a bill is pending that would allow beaches at state parks and forests without lifeguards to be open for swimming. The state Assembly passed the bill, and it is pending in the state Senate.

Assemblyman E. Scott Garrett, R-Sussex, said one of his considerations in introducing the bill was that state parks are having trouble finding enough lifeguards to keep swimming areas open.

The trend toward fewer lifeguards worries W. Chris Brewster, chairman of the certification committee for the U.S. Lifesaving Association and head lifeguard in San Diego, where there are 6,000 rescues a year.

Signs saying “No Lifeguard on Duty” or “Swim at Your Own Risk” are a recipe for disaster, Brewster said.

“You’re depending on the judgment of the person reading the sign to determine whether it’s safe to swim,” he said. “Children in the 1-to-14 age range are not known for using good judgment.”