In 1985, with his wife, Beth, Mr. Larsen opened the Net Result on Beach Road in Vineyard Haven. This Sunday, July 4, the market will celebrate its 25th birthday, to the day. To mark the occasion, the Larsens will offer free tee-shirts to the first 1,000 customers on Sunday, and a few lucky winners will come away with sweatshirts and $25 gift certificates.

For Mr. Larsen, 56, making a living off the sea is all he has known and all in the family. His grandfather, Daniel, left his native Norway to go to sea in the first years of the last century. After circling the globe three times, he decided that Martha's Vineyard was where he wanted to settle, to fish and to raise his family. In the early 20s, he brought his wife and four children — Olga, Nicka, Dagbard, and Bjarne to America and to Chilmark. His youngest child, Louis, was born here in 1925.

As much as the Net Result marked a beginning for Mr. Larsen, it also marked the ending — of his life as a commercial fishermen. The reliable profitability of commercial fishing, once a given in local waters, was over. For years, swordfish was the principal prey for Dagbard, Bjarne, and Big Louie, as Mr. Larsen's father was known, all fishing out of Menemsha. Often they harpooned a plentiful day's catch within sight of Gay Head. Come late afternoon on many summer days, a crowd would gather along Dutcher Dock to watch huge, healthy swordfish hoisted onto the dock and into the fish markets.

Things started to change when mercury was discovered in swordfish in 1971. The fishery was shut down in the U.S. and Canada, although limited fishing was still permitted in Massachusetts.

Through the 1970s, Mr. Larsen kept chasing, and catching, swordfish — with his father on the family boat offshore and with fellow Chilmarker Albert Fischer on a smaller boat inshore. By 1979, however, when the fishery was re-opened, a sea change was at hand.

Sophisticated new fish-finding and navigation devices tipped the hunter-prey balance dramatically in favor of the hunter, effectively wiping out inshore swordfish stocks, and harpooning with them. The handwriting was on the bulkhead, and Mr. Larsen decided to come ashore and apply the lessons he'd learned at the family fish market in Menemsha to a year-round market down-Island. Still in the family, Larsen's is now owned by his sister Betsy, who shares her brother's capacity for hard work and his ready smile, two traits they probably inherited from Big Louis, who to this day accompanies every greeting with a warm, direct smile. Sister Kristine works with Betsy in Menemsha, and the fourth sibling, Danny, owns and runs the Edgartown Seafood Market with his wife, Marie.

"I grew up with my father never around, because he was always fishing, and I decided I wanted to watch my kids grow up," Mr. Larsen said earlier this week about his decision to open the Net Result. "Little did I know that I would see them less than when I was fishing." At the time, he and Beth had two boys, four-year-old Travis and Hans, two. Andrew, now 20, was born four years later.

Starting the market posed new challenges, most of them bureaucratic. "I went to Boston on the July 3rd to pick up the license from the Division of Marine Fisheries so we could open," Mr. Larsen said. "We didn't plan it that way: we wanted to open on May 1, but things kept coming up."

At first the Net Result occupied one third of its current space, sharing the building on Beach Road with Martha's Music and Classic Capers Catering. It was small, but it didn't take long to become a fixture for residents and visitors who wanted fresh fish year-round.

For the first ten years, Mr. Larsen never took a day off between May 1 and Columbus Day. He still rousts himself well before first light, most days, to get to the market by 4 am and start cleaning fish, ensuring that the product in the cases is as fresh as possible before opening. "We open at 6 in summer [9 in winter], but the door's always open when I'm here," he said, "or Jeffrey."

Jeffrey Maida, who also grew up in Chilmark, has been around fish forever — netting bait in Menemsha Basin as a child, mating on sportfishing boats, lobstering on his own. He's been working alongside Louis and Beth at the Net Result for the last 24 years, and they've relied on him from the outset. "I couldn't have done this without him," Mr. Larsen said. "It's that simple."

Of course it's never simple to start a business from scratch and grow it steadily for 25 years. A staff that varies from 8 to 30, winter to summer, helps keep things running smoothly, but the driving force is Mr. Larsen's apparently inexhaustible energy. Most likely it goes back to his early days swordfishing with his father, when he would be in the crow's nest looking for fish just after first light, before fish come to the surface where they can be spotted, and struck. "They used to call my father Lucky Louie, but there wasn't any luck," he said. "Other boats would lay to, and they'd be below playing cards, waiting for the fish to show. We didn't see many fish that early, but we saw some. That's why we were lucky."

Nor does luck play a role when it comes to offering quality seafood. From the beginning, Mr. Larsen has set high standards and he has maintained them. "I assume my customers are as smart about their food as I am, and why try to pull anything over on them," he said. Especially when many of those customers are friends or neighbors.

Whenever possible Mr. Larsen sells fish and shellfish harvested in Island waters. To offer his customers a range of seafood year-round, however, Mr. Larsen has imported fish from the outset.

In the early years, the market sent as much fish off the Island as it brought on. But as fisheries declined and regulations increased, Mr. Larsen could no longer count on a steady supply of fish being landed on the Island, and the export part of his business fell off. Today, a truck goes off Island every day to pick up fish in Boston and New Bedford. As a supplier of many restaurants on the Island, today the Net Result's ratio of retail to wholesale is about 50/50.

Though it's been remodeled, expanded, and now includes a thriving take-out business, the Net Result hasn't really changed that much in 25 years — neither in mission nor in mood. The Larsens still keep the community supplied with the best seafood available, and customers keep coming out the door with a lift in their step.

It's a winning combination, and here's hoping that Sunday's 25th anniversary celebration marks the start of 25 more lively, thriving years for the Net Result!