A few months ago, Dennis Diamond didn't know a bass bug from a sand flea. His idea of a great catch was a sale on flounder at Safeway. And the only fishing gear in his Silver Spring home was a 20-year-old tangle of rusted parts and tangled line that couldn't have fooled the goldfish in his wife's bowl.

So when I invited the 35-year-old construction contractor and longtime friend to go fishing, I didn't expect him to catch much more than a summer breeze.

Instead, he caught a world record-sized fishing fever.

"I got it bad," said Diamond, who called me one morning at 7 a.m., a week after our fishing trip, to report his condition. The night before he had cracked triple figures buying a new rod and reel, a tackle box and enough multicolored lures to fill it.

Diamond had begun buying hard-core fishing magazines and sneaking out of bed at night to practice tying exotic knots. He had even started speaking fish lingo. Submerged trees were now "underwater structure." Back casts caught in overhanging trees sounded much better when described as "improper presentations."

The one thing the magazines hadn't taught Diamond was how to catch fish.

"You don't know how bad it is," he said in a voice that sounded hurtfully small coming from a body big enough to scare Bobo Brazil. "When I go home my 2 1/2-year-old twins look up at me with those little eyes and say 'Catch fish, Daddy?' With lips quivering, they turn away disappointed.

"Then the dog comes up sniffing. He turns away disgusted. Finally the wife starts in. It's a tough thing for a man to endure."

Last week, some of Diamond's friends decided to treat him to a full day of fishing with Charlie Taylor, a professional guide who works the Potomac River. Taylor fishes the Potomac or the Chesapeake Bay about 200 days a year. During the winter he fills the swimming pool in his backyard with bass and practices catching them each morning after breaking the ice. If Taylor tells you he can catch a largemouth bass in a mud puddle, don't bet against it.

We figured if anyone could break Diamond's run of bad luck, Taylor could.

The night before the fishing trip, Diamond's wife Cathy surprised him with a Fish Incentive Dinner. I brought bluefish and sea trout to grill. Others came with fishing lures and mock gifts like a fishing dictionary that described "advice" as "two or more pieces of contradictory angling information contained in a single phrase or sentence."

Plums were decorated with candy Lifesavers and gumdrops to resemble bobbers. A cake was decorated to resemble a blue-green sea, alive with plastic fish and a stick fisherman.

When we met Taylor the next morning at Belle Haven Marina in Alexandria, Diamond had so much fishing momentum behind him, he should have caught a bluefin tuna.

"The winning bass in the last two Potomac River bass tournaments have been pulled out right beside that stump," said Taylor, directing Diamond to stand on the back platform of his bass boat and cast near the lush, green shore of a cove. No bass went for the lure, but a few casts later Diamond did pull out a small catfish. Hope sprang eternal.

Except for two small perch, however, we would catch no more fish during the next six hours. Taylor took us to all of his regular places and some of his top secret, guaranteed, bass-busting spots. Everywhere the fishing was the same. No bites and no nibbles. The only fish we saw were two plastic ones that Diamond's wife had devilishly placed inside his peanut butter and jelly sandwich.

"Charlie, do you believe that some people are just born jinxes?" someone cruelly asked.

"No I do not," answered Taylor firmly. Then, with a sidelong look at Diamond he continued, "Not even Dennis Diamond."

Because of prior commitments, we had agreed to quit fishing at 4 p.m. At 10 minutes until 4, Taylor looked more than a little worried. He claimed to have caught at least one bass each of the last 239 times he had fished the Potomac. That record appeared ready to fall.

With just seconds left on the clock, however, Taylor hooked and landed a three-pound largemouth. Almost immediately I caught a smaller one. We both felt bad for Diamond, but time had run out.

Back at the marina, Diamond and I stood on the sea wall above the sloping, concrete boat ramp, trying to figure out how to put the best face on this day for his wife and kids. Taylor had backed his station wagon almost into the water so he could power the boat onto the partially submerged trailer.

When the weight of the boat dropped onto the trailer, the station wagon suddenly began to roll backwards. Before I could move, Diamond was sprinting toward the car. When he tried to stop, however, his feet slipped on the gravel, tossing him face first onto the concrete ramp 3 1/2 feet below.

Without pausing to check his wounds, Diamond climbed headfirst into the open door of the car and hit the brake.

Three hours later, Diamond walked into his home with his left arm and wrist enclosed in a fiberglass cast. He had broken a small bone in his wrist, but he looked faintly pleased.

"I got the biggest catch of the day," he said as his twins raced up to greet him. "I caught a station wagon."