The Sunshine State received 40 of the 70 designated "beach bums" from the report by the Natural Resources Defense Council, which gives the tag to U.S. beaches where waters are not monitored, that don't use EPA-recommended criteria and that have known sources of pollutants.
But Florida's Key West, which worked to improve sewage that affected the area's coral reefs as well as the water, was praised for its efforts. California's San Diego and Los Angeles were also awarded "beach buddy" designations, along with Salem, Massachusetts, and Branford, Connecticut.
The council singled out Oregon and Louisiana as the coastal states that do not have any regular monitoring or public notification programs.
Across the country, the number of beach closures and advisories was up, almost 20 percent more than last year, the non-profit group said.
"This is the time of year when people are heading to the beach, people are expecting to have fun, looking forward to a day in the sun, a day in the sand, a day in the water," said Nancy Stoner, the council's Clean Water project director.
"What they need to be concerned about is dirty water, and the possibility that they and their families will get sick from swimming in polluted beach water."
About half of the nation's freshwater and ocean beaches were closed last year for unknown reasons, but the known leading causes include raw sewage or contaminated storm water, which includes pollutant run-off from the ground.
Since the environmental group began this annual survey 12 years ago, 12 coastal states have initiated or expanded monitoring programs.
The numbers are up in part this year because more states are actually monitoring water quality, but the non-profit group also said that states have inconsistent standards across the country.
Last year was Florida' first year participating in the healthy beach program, which calls on counties to monitor the state's 316 beaches. All but six of Florida's bum beaches were in Brevard County, home to Cape Canaveral, Cocoa Beach, Melbourne and Merritt Island.
Florida Department of Health spokesman Bill Parizek told Reuters that monitoring was already ongoing in Brevard County's most visited beaches, which were not mentioned in the survey.
"We've got to look at this and see where these beaches are," Parizek said, adding he knew that one bum beach the group listed had been closed for years.
"I think our beaches all in all are good beaches -- Florida still has some of the best beaches in the country," he said, adding his department surveys the water quality of 304 different beaches every two weeks.
Puerto Rico also began monitoring last year, but does not tell the public when water quality standards are not met.
Among states that have regularly monitored water quality for some time, California's beach advisories and closing went up 14 percent year, but the council said greater rainfall and 14 new beaches may have contributed to the increase.
On the East Coast, New Jersey's popular beaches, including Atlantic City, were shut 125 times last year, compared with 33 the year before.
New York state does not require its counties to monitor swimming beaches, and the survey added that timely and effective public notification of dirty beaches "continues to be a problem" for New York City.
For healthy beach visits, the environmental group recommended swimmers follow some basic general rules: open ocean environments are normally safer, as are those bodies of water farther removed from developments.
Avoid swimming after heavy rainfall, which spreads ground pollution and, for those very concerned people, keep your head out of the water, said Sarah Chassis, director of the group's water and coastal program.
By Niala Boodhoo