The worldwide oil price crisis is hitting Island commercial fishermen hard. Already struggling with more restrictive regulations and declining landings, Vineyard small-boat fishermen now face fuel prices that have doubled in a year.

Capt. Wayne Iacono of Chilmark is a commercial lobsterman who fishes out of Menemsha. With the decline in lobsters in Vineyard waters, he already had taken a second job as a plumber.

And with the price of fuel so high this summer — between $4 and $5 per gallon — he and his colleagues have had to redraw the areas where they drop their lobster pots. Captain Iacono said he doesn’t go out to his old favorite spots.

“Lobsters are slow right now so we aren’t going as often,” Mr. Iacono said. “For myself, I am fishing closer to home and I am seeing a lot more gear out there.”

When the lobster fishery was less constrained by the price of fuel, a captain could pick his favorite spots. Distance wasn’t so much a factor.

“Cox Ledge is where you’d go,” Mr. Iacono said. The ledge is halfway between the Vineyard and Block Island, about 23 miles southwest of Menemsha.

“Now I’m staying within 10 miles of the bight. That is the furthest I am going,” he said.

Vineyard lobstermen have at least one incentive: they are receiving a higher price for the lobsters they land.

“I think everyone here is getting $7 [a pound], which is pretty good,” Captain Iacono said. “I think on the mainland the lobstermen are getting $5.50.”

Vineyard conch fishermen are less fortunate. Capt. Tom Turner of Edgartown said the price he is being paid for his conch is about the same he received back in 1993.

“In those days the price of fuel was 86 cents a gallon,” Captain Turner said. “Today the price of fuel is north of $5 a gallon. We can’t get a raise.”

Conch are a shellfish harvested in Nantucket Sound and adjacent waters. About a dozen conch fishermen are based on the Vineyard.

Capt. Tracy Sharples of Edgartown, another conch fisherman, said that when he started fishing in 1991 bait was $7 a bag. “Now it is $24 a bag,” he said. He said he is getting $1 a pound for small conch and $1.50 a pound for large.

Earlier this week, Captain Sharples said, he purchased 103 gallons of fuel for his 36-foot boat, the Patricia J. “That $500 would have lasted longer in Las Vegas than it did when I bought fuel,” he said.

The commercial fishermen in Edgartown do get a small break from R.M. Packer Co., a fuel supplier based in Vineyard Haven.

Packer employee Don MacFarland delivers fuel to the boats at 6 a.m. on Mondays and Fridays. He said he was able to obtain the necessary permits and support from Edgartown fire chief Peter Shemeth.

Mr. MacFarland drives a low-sulphur oil truck that carries 2,300 gallons. When the fishermen buy fuel at the same time, it is worth their special trip to the dock.

For commercial fishermen who work on draggers, the sharp rise in the cost of fuel may be more of a defining moment than all the restrictive regulations enacted in the past 20 years due to declining fish stocks.

“We are at the bottom of the food chain. We can’t increase the price of our fish,” said Capt. Gregory Mayhew of Menemsha, who operates a 75-foot fishing boat Unicorn with his son Todd and daughter Gwen.

“This is the most definitive thing in lives of the commercial fisherman,” Mr. Mayhew said. “We are getting prices lower than we got 10 years ago, even though the price of fuel has doubled or quadrupled.” “I have talked to fishermen who have put their boats on the market,” Mr. Mayhew said. “One of the boats in Point Judith which is the same power as mine is owned by a fisherman who runs a family business. He has put his boat on the market. He can’t get good crews to go because they aren’t making more money ashore.”

Years ago, Mr. Mayhew said, “You could make more money than a plumber or an electrician, until the government got involved in the mid-1970s.” Now they make less.

Mr. Mayhew recalls paying 15 cents a gallon for fuel in the early 1970s.

“Fish prices back then were not that different from what they are now,” he said. “The fuel price a year ago was less than $3 a gallon. It has gone up a dollar.”

In April, Mr. Mayhew said, he was hesitant about jumping into the squid fishing season that takes place in Nantucket Sound: “I didn’t go looking for squid in the first few days of the season because of the risk of not catching anything and still having a large fuel bill.”

Captain Mayhew said he has taken new steps to economize the operation of his boat, down to making decisions about running a small motor that runs the generator. “It costs $100 a day just to run the generator,” he said.

He contacted experts in the engine service department at D. N. Kelley & Son Inc. Shipyard in Fairhaven to learn about ways to economize. He learned his diesel engine consumes nine gallons an hour when the engine is going at 1,400 revolutions per minute and 14 gallons an hour when the engine is running at 1,600 rpm.

“The difference can be as much as $20 an hour,” the captain said. “It is just like a car. The more you step on the accelerator the more you spend. We had to be more mindful. I am running the boat slower,” he said.

Captain Mayhew also made another discovery this spring. “It costs me $300 to bring my fish to New Bedford and come back to Menemsha. I decided it was cheaper just to take the fish to New Bedford by truck, if I didn’t have too much.

“Now I only go to New Bedford [in the boat] when I need fuel, ice, repairs and have enough fish to unload,” the captain said.