A half-day fishing trip on a Delaware Bay headboat is a perfect introduction to saltwater fishing for tourists, kids and well-fed anglers who don't want their afternoon interrupted by a lot of fish. The boat doesn't leave Fisherman's Wharf until 1:30 p.m. and is back at the dock by 6. The ride alone is worth the $10 fee.

So when Lee Blount pulled his 100-pound sea creature to the surface, the 20 customers on the Thelma Dale III oohed and aahed.

"You big monster you," said Blount, a 33-year-old paramedic from Warrenton, Va., as the giant sea turtle he had inadvertently snagged stuck its head out of the water to see what was reeling it in by the flipper. "I bet you didn't think you'd be spending your afternoon like this."

Tourist fishing is the easiest way to find fish this side of the supermarket. If you have the money for a spot on a boat, and a few extra dollars to rent a rod and reel, all you need to do is stand by the rail and hold out your hand. A mate will tie all the knots, bait your hook, even show you how to let out line and reel it back in. And because the Atlantic and its estuaries in this area are generally rich with fish, you are almost certain to catch something.

This year, however, the guarantee is limited. In both the Chesapeake and Delaware bays, and Atlantic waters close to shore, normally eager fish are playing hide-and-seek. Sea trout and striped bass have been a disappointment and bluefish that are usually attacking bait in bunches at this time of year are scarce.

"If I had 25 more years in me I could go find the fish," says Capt. Harry Parsons, the 78-year-old patriarch of the fishing fleet that works out of Lewes, where the Delaware Bay meets the Atlantic. "But the way things are now, you have to go pretty far out in the ocean to find them."

Parsons is a trim, soft-spoken man with a round face as bright as a sunrise. He has been fishing the bay for 44 years. He now has a son and grandson who work with him as charter boat captains. Their territory is choice, close to both fish and fishers. Because Lewes is just a few miles north of Rehoboth Beach, it attracts the curious along with the committed anglers. And Parsons hates to disappoint either group.

"The fishing isn't what it used to be," says Parsons, who is called "Pappy" around the wharf that he built out of a marsh. "You can't make 'em bite if they're not there."

Parsons blames pollution, pesticides and other runoff caused by development along the Delaware River for the general decline in sport fishing. And he blames the "government" for not applying stricter environmental controls to halt it.

There is some irony to his complaint. People around the wharf are more used to hearing Parsons complain about too much governmental interference. From a shady seat in the stern of one of the five fishing boats his family owns, Parsons points out spots where he was prevented from building improvements on his land.

"I wanted to put a bulkhead over there," says Parsons, pointing to a thin strip of dirt and grass across a canal. "But the environmental people said snails were breeding there and you daren't disturb the snails. There's so much red tape it will drive you crazy."

Parsons was born in a rural crossroads town just 35 miles from his wharf. He still talks country slow, but after living in Philadelphia for two decades, his mind works with city slicker speed.

"I just went up there for a couple of weeks and stayed for 19 1/2 years," says Parsons with a grin. "I guess it didn't scare me too much."

Parsons drove trolley cars and the buses that replaced them. He bought a storage garage that went bust, then recovered in time to lose money in the stock market crash of 1929. By the time the Depression was in full swing, Parsons decided to put some money where it would keep his family fed. In 1938 he bought a fishing boat and began to build his future.

"During the Depression a lot of people were a little on the hungry side," says Parsons. "I bought the boat for the wife and kids to live on and have something to eat."

Parsons still takes fishing parties out on the Bay, but leaves the day-to-day operation of his wharf, fish market and restaurant to younger Parsons. "I don't jump around like I used to, but I keep moving."

Rick Yakimowicz, a 20-year-old charter captain, pilots our fishing party out of Roosevelt Inlet and into the Bay where it meets the Atlantic. On board are 20 anglers, almost half of them fishing on the ocean for the first time. Expectations are modest.

"I'm just out here for the fun of it," says Raymond Heimbach, a college professor from Pennsylvania who has taken an afternoon off from sunning at the beach to try fishing. His 10-year-old son Ryan is less content. He is determined to catch fish.

Perhaps the most serious fishermen on board are two teen-agers from Bowie, Md., Mike Knaly, a red-haired, freckle-faced 15-year-old and a classmate at John Carroll High School in Washington, 16-year-old Tony Bray.

"I'm after shark, marlin, anything big," says Bray.

Together the two bring in four flounder and one sea bass, which is a disproportionate share of the 20 fish that are caught during the entire afternoon of drift fishing. Raymond Heimbach and his son are skunked. On the trip back to shore, Heimbach, a tourist out for a day on the water, says the trip was worth the price. But his son stares at the green water with the disappointed eyes of a real fisherman.