ROME (AP) — The swimmers on the pool deck in Rome are ogling each other’s high-tech bodysuits like fashionistas on the runways of Milan, thinking of gliding into history with yet another record-smashing time.

The leaders of the sport, however, are saying: Not so fast.

With all the astonishing technological advances of the past year and a half threatening to turn swimming into “a joke of a sport,” as one top coach put it, officials on Thursday took a cautious step toward reining things in.

FINA, the sport’s governing body, approved a proposal backed by USA Swimming that adds two key words to a rule stating: “No swimmer shall be permitted to use or wear any device that may aid his speed, buoyancy or endurance during a competition.” The new rule bars “any device or swimsuit” that aids performance.

The new rule comes just as Michael Phelps and Co. prepared to make a splash at the world swimming championships

“Now the line is in the sand. This week. It cannot go past this week,” said Alan Thompson, longtime leader of the Australian national team and one of swimming’s most influential figures. “This is a great sport. There are great people involved in it. We must return it back to the credibility it once had.”

That credibility has certainly been threatened by a mind-boggling assault on the record book. Last year, 108 world marks were set, off the charts even in an Olympic year with all the top swimmers in peak form. The trend is still going strong in 2009, with nearly 30 records falling already – an astonishingly high number coming on the heels of the Beijing Games, with many top swimmers taking time off, reducing their training regimen or struggling to stay motivated.

Some were beginning to wonder, Thompson among them, if any current records will still be standing after the eight-day world championships, the biggest meet outside the Olympics.

“We felt like that was a good victory,” Mark Schubert, head coach and general manager of the U.S. national team, told The Associated Press, when asked about the rule change.

Still, there’s plenty of skepticism that FINA will follow up on the rule change with meaningful restrictions — especially after it gave the green light to most new-age suits for Rome — and whatever is done from here won’t have any impact on these championships.

“When you put that thing on, it feels amazing,” said American backstroke star Aaron Peirsol, who wears the Arena X-Glide. “It definitely feels like something different than the suits we used five or six years ago.”

Swimsuit manufacturers also are a major source of funding, whether it’s a top national programs such as the U.S. or Australia (both sponsored by Speedo), or a top swimmer such as Phelps who gets millions from his endorsement deal with the same company. Speedo doled out a $1 million bonus to its most famous athlete after he broke Mark Spitz’s record for most golds in a single Olympics.

“FINA doesn’t really understand what they want to do,” Peirsol said. “They have no idea. I wish they did. But if they had any idea, they would have made their minds up last year. They opened up their own can of worms and the floodgates opened.”

Some have suggested going back to old-style suits like the ones worn until the 1990s, remnants of an era when everyone thought the less fabric in a suit, the better. Male swimmers wore barely there briefs, while the women wouldn’t have dreamed of covering their arms or legs.

Everything changed with the introduction of bodysuits at the 2000 Sydney Olympics, made of fabrics that reduced the resistance of the water.

Then, in February 2008, the technological arms (and legs) race really took off. Speedo unveiled the LZR Racer, developed with help from NASA and worn by most swimmers setting records in 2008. That included Phelps, who became the winningest Olympian ever when he captured eight gold medals in Beijing, seven of them with world record times.

FINA barely seemed to notice, which left the door open for other companies to take on the LZR. Speedo’s signature suit is now considered sooooo last year up against the polyurethane attire developed by Arena and Jaked, the latter a small Italian manufacturer that seemingly came out of nowhere.

Suddenly, the Jaked suit is all the rage.

“That was the one I felt the most comfortable in and felt would give myself the best opportunity to swim fast,” Australian breaststroke star Brenton Rickard said.

The ever-changing suit landscape prompted Speedo to allow its endorsed swimmers to switch to another company’s suit if they felt it would help their performance. Even so, those who took the offer can’t help but wonder if it might have financial ramifications down the road.

“I’ve got my fingers crossed,” said another Aussie, Andrew Lauterstein, who won three medals in a Speedo LZR at last year’s Olympics but will wear a different suit in Rome. “My management had a meeting with them (Wednesday) regarding my decision.”

Not surprisingly, both Phelps and fellow American star Ryan Lochte have stuck with Speedo, the company that provides a large chunk of their take-home pay.

“I’m still faster than most people in those other suits,” Lochte said. “I feel like it’s a challenge, because those other suits are supposed to be faster.”

FINA insists that it is taking steps to bring everything under control.

The U.S. was expected to present another proposal Friday that would prevent suits from covering anything beyond the shoulders or below the knees, coinciding with Julio Maglione of Uruguay taking over from Mustapha Larfaoui as FINA’s president.

“It will be interesting to see if that passes as well, but certainly … there was a strong sentiment against what is going on,” Schubert said.

FINA’s 22-person executive bureau is also expected to change in Friday’s congress. Next week, the new panel will decide on rules that take effect in 2010.

“That’s going to be another step forward,” executive director Cornel Marculescu said. “The most important thing is defining rules for buoyancy, thickness, permeability and compression – and developing scientific tests.”

Thompson said it’s time for the powerhouse nations, mainly Australia and the U.S., to take a more active role in deciding the rules.

“We’ve got to step up and say what we think,” the coach said. “Everyone has been sitting back and waiting for FINA to show some leadership. Well, they have to show leadership right now or we have to speak to them to make sure they do. I don’t want any drastic measure,” such as splitting off to form a new organization.

“But I think everybody needs to be much stronger.”

The swimmers are tired of all the talk about suits, which already has disrupted their preparations and figures to be an overriding theme in Rome.

“It kind of stinks for people who do well from their own natural abilities and hard work to have people owe that improvement to the suit,” American Matt Grevers said.

There’s a good side to it, though. The debate over swimsuits has kept people talking about the sport beyond its usual once-every-four-years limelight.

“I love the fact that swimming is getting as much publicity as it is,” U.S. sprint specialist Cullen Jones said. “You have to say part of that is the suit.”