A federal judge on Wednesday sentenced the Rev. Al Sharpton to 90 days in jail for trespassing on U.S. Navy land as part of a protest against military exercises on the Puerto Rican island of Vieques.

"If Martin Luther King were alive, he would have come to Vieques and raised these issues," the New York civil rights leader said, appearing before Judge Jose A. Fuste.

Sharpton was taken into custody for transportation to the federal prison in suburban Guaynabo.

He was arrested May 1 with a dozen other protesters. At least 180 people were arrested in an attempt to stop the exercises April 27 to May 1, which the demonstrators claim are a hazard to residents' health. The Navy denies the exercises have led to any health problems.

The sentencing came one day after Sharpton hinted he might make a run for the White House in 2004 and political analysts said the jail time won't hurt him.

Indeed, analysts indicated that the publicity likely will help him gain support among some and notoriety elsewhere.

"He will get a lot of attention and that's something that he's always covets, as a community activist," said Lee Miringoff, a pollster at the Marist Institute for Public Opinion in Poughkeepsie, New York. "His actions are not necessarily to appeal to all of the electorate. In this instance, this is one that he calculated, or understood, would be intensely supported by some of the electorate."

Sharpton was convicted of a misdemeanor and because he has been arrested before for civil disobedience in New York, was sentenced as a repeat offender. He also was fined $500.

Sharpton attorney Sanford A. Rubenstein said lawyers are working to file an appeal with the First Circuit Court of Appeals in Boston on Thursday, and will ask an appeals judge to allow bond. Fuste did not allow Sharpton a stay of his sentence pending his appeal.

He complained Sharpton had only one day's notice of the hearing in Puerto Rico, which prevented him from compiling a proper case.

Eleven other activists who were arrested with Sharpton also appeared in court Wednesday. Nine were sentenced to 40 days in prison and fined $500. They included New York City Councilman Adolfo Carrion, New York state legislator Jose Rivera and Bronx County Democratic Party chairman Roberto Ramirez.

Two defendants were put on probation because they are ill.

Other high-profile protesters arrested during the demonstrations included environmental lawyer Robert F. Kennedy Jr., Rep. Luis Gutierrez of Illinois, actor Edward James Olmos and New York labor leader Dennis Rivera.

Earlier this month, Puerto Rican independence leader Ruben Berrios was sentenced to four months in jail, the stiffest sentence given to the anti-Navy protesters so far. Berrios had refused to recognize the jurisdiction of the U.S. court and did not mount a defense.

The Navy has used its range on Vieques, population 9,400, for six decades and says it is vital for national security. Critics say it poses a health threat, which the Navy denies.

Opposition to the exercises grew after a civilian guard was killed on the range in 1999 by two off-target bombs. The Navy has since stopped using live ammunition, and islanders will vote in November whether the Navy must leave in 2003 or can stay, resuming the use of live ammunition.

"Now the case of Vieques won't be an isolated case," said Jose Paralitici, a university professor and spokesman of the group All Puerto Rico With Vieques. "Civil disobedience is going to grow. The sentences given to Sharpton and other demonstrators appear excessive. They aren't common delinquents."