Dan Jacobson may always be questioned. Some northern fishermen may think of him as a thief, as if the Boynton Beach man were a backyard burglar who snuck into their homes and tried to take their prized possessions.

And all he did was catch a big fish. A muskie.

But Jacobson learned you never get between a big muskie and big muskie fishermen.

Jacobson caught a potential world-record muskie in August 1993 on his annual fishing trip to Canada. It was a trip he and his buddies had taken for 18 years.

This time it was more than a ritual. Jacobson hooked a 63-inch muskie out of Lac Seul in northwestern Ontario. He was required to release the fish because of lake rules — but not before much videotaping, measuring and picture taking.

Still, that proof and nine witnesses were not enough to verify Jacobson's fish as a catch-and-release record.

His detractors say he made important mistakes in fighting and weighing the fish, mistakes they never would have questioned if Jacobson himself had not volunteered a videotape of the event.

"My personal opinion is that these are muskie fanatics. I don't fit into their group. I've only caught two muskies before," said Jacobson, who practices law in Fort Lauderdale and is a veteran saltwater angler. "These guys fish for hours and hours. These people are devoted to muskie fishing."

Muskie fishing is addictive, the devotees say. And like any addiction, those in its throes take its pursuit seriously.

At first, Jacobson was welcomed. The National Fresh Water Fishing Hall of Fame in Hayward, Wisconsin, asked him to apply for the record. The Hall has recognized catch-and-release feats for the past 1 1/2 years.

The previous muskie release record was 57 inches caught by Curt Fenton on the same Ontario lake.

Jacobson received a citation and a glorious letter about his achievement. An author called for an interview and photo.

"He asked, would I like a video?" said John Detloff, a muskie guide, historian and author at Chippewa Flowage in Wisconsin. "I was excited because that's really something to capture that on film. But when I looked at it and once I saw the measurement, then it was unfortunate. It was evident in the video that the tape measure went past the tail to some degree."

Detloff said others who saw the video complained that the fish was smaller than its stated size. Detloff believed Jacobson had made a simple mistake.

"He caught a fish that was literally too big to measure," said Detloff, who is writing a muskie book and has also discredited a weighed catch — a 69-pound, 15-ounce muskie in 1957 by angler Art Lawton. "This fish was pushing 5 feet in length. ... He made the measurement in the water. He did the best he could, but it wasn't an accurate measurement."

Detloff and Jacobson corresponded. Detloff sent a detailed letter showing how he compared such things as the 7 7/8-inch lure, Jacobson's height and the length of the boat to the size of the fish.

Jacobson has said his measurement was not intended to be precise. It was quick, and at the time he didn't suspect it would be used for world-record qualification.

Hall officials had their own problems with the video.

"Dan did legitimately bring the fish to the boat. At that point, he gave the rod to a friend in the boat," said Hall director Ted Dzialo. "The fish made several runs. Dan did handle it for one of the runs. But his companion handled the rod for two of the runs. On that basis, we disqualified the record."

Jacobson was incredulous. The fish was docile. It never made another run, he said. He simply gave the rod to his friend so he could personally handle the fish and release it.

"If they said, 'Look, you didn't take a precise measurement,' that would be better than saying I had help bringing it in, because that's just not true," he said. "They're not happy. I cast this rod and this big fish hit it and they're just not happy about it."

Jacobson said Detloff told him he would look like one of the "good guys" if he relinquished the record. Jacobson retorted: "I am one of the good guys."

But the Hall took away the record anyway. Dzialo said if there had been no videotape, the mark would have stood. In the face of recorded evidence, though, there was no choice.

Jacobson said the Hall never questioned any of the witnesses.

As a lawyer, Jacobson said he has considered suing to have the record reinstated. But that would mean he's taking this as seriously as his detractors. But he's tempted.

Last month, when he and his friends went to Canada, Jacobson was a local hero. Someone asked for his autograph at the airport.

A few muskie fishermen have written angry letters urging him to act.

But Dzialo said he has received 40 to 50 letters from anglers complaining about Jacobson's measurement. Like largemouth bass in the south, muskies can bring northern anglers to blows.

Said Detloff: "When you finally tie into a big muskie and the excitement is there, the fish is usually an explosive, wild, jumping fish. And you say, 'Wow, I want to experience that again.'

"We live and breathe muskies in northern Wisconsin. Everything revolves around the muskie."