Dan Snow loves to fish. And what he loves to fish for the most are bass, the big, spiny-finned ones that choke hundreds of pristine lakes in Cuba like autumn leaves in a pool. "The best in the world," he says.

Trouble is, the U.S. government bans travel to the communist island. Similar restrictions apply to Vietnam, North Korea, Cambodia and Libya. Exceptions are made, such as for scientific or journalistic trips, but the U.S. government still limits the amount of money visitors can spend in Cuba to $100 per day.

Research trips are what Snow claimed he was running when he started to include a few ichthyologists on his excursions to Cuba after the Reagan administration cracked down on tourism in 1982, following a loosening of travel restrictions under the Carter administration.

The government didn't buy it. Snow was sentenced in April to 90 days in jail -- he's currently serving weekends -- was fined $5,300 and ordered to serve five years' probation and 1,000 hours of community service for a December 1987 trip. He could have been sentenced to life in prison.

"If you can go to the Soviet Union, why can't you go to Cuba? If McDonalds can do business with the people who have all the missiles pointed at us, why can't Americans go fishing in Cuba?" Snow, 51, asked in a recent telephone interview from Kingwood, near Houston.

"The U.S. claims to be the freest country in the world, so let's be the freest country. I don't know of any other democratic country that restricts its people in peacetime from traveling," he said.

Rep. Howard L. Berman (D-Calif.) agrees and is sponsoring a measure -- dubbed the Free Trade in Ideas bill -- that would take away the president's power to prevent travel to nations under economic embargo, but increase his power to restrict travel to parts of the globe where Americans face imminent physical danger.

"Any restriction on the travel of American citizens is an impingement on a fundamental, constitutionally guaranteed right," Berman told the House Foreign Affairs subcommittee on international economic policy and trade in March.

"Any interest that the United States had in depriving the {proscribed countries} of the currency of American travelers was far outweighed by our interest in accelerating the spread of democratic ideas and information by supporting the travel of our citizens," he said.

The bill, which could come up for a vote after Congress returns from summer recess in September, also would limit U.S. power to restrict importation of foreign-made educational films.

But the Treasury Department, which recently threatened members of a Vietnam veterans group in Akron, Ohio, with fines and imprisonment for organizing tours to that Southeast Asian country, maintains that the bill would be a major step toward de facto normalization of relations with governments that the United States has been trying to turn into international pariahs.

The bill would "unduly restrict the president's authority to conduct foreign affairs," R. Richard Newcomb, director of the department's Office of Foreign Assets Control, told Congress in March.

He also said it would "permit the development of full-blown tourist industries, fed by U.S. dollars, to support some of the most repressive regimes in the world."

But the bill's backers argue that the travel ban violates the Helsinki Accords, the international agreement not to restrict freedom of movement, which the United States has repeatedly accused the Soviets of violating.

"I spent my time in the Marines. I was willing to die for my country to protect it from the fascists, the communists," Snow said. "I'm not going to let the U.S. take away my rights. It doesn't matter who takes away your liberty, if it's taken away. If Mikhail Gorbachev tried to take away our liberties we'd fight. Why shouldn't we fight Ronald Reagan or George Bush if they try to take it away?"