“There is just not a lot of business out there right now for the offshore service companies,” said Court B. Ramsay, president of Aries Marine of Lafayette, which has a fleet of 26 boats used in repairing oil and gas platforms in shallow waters. “It would be a shot in the arm for sure, for my business and many business like mine, if we can get some relief from some of these rules.”

Statistics from the Greater Lafourche Port Commission, which operates the port here about 160 miles from Lafayette, show that as many as 450 boats passed in and out of the piers each day, mostly to serve the oil and gas industry, during drilling’s peak. Now there are about 300. In addition, diesel fuel sales have dropped from about 40 million gallons a month to about 20 million, said Chett Chiasson, the port’s executive director.

The fall in oil prices certainly contributed to the decline, Mr. Chiasson said, but he also blames the Obama administration.

“There were regulations that were not necessarily increasing safety, but they were just increasing the cost of the activities in the oil and gas industry and thus hindering their ability to keep operating in the Gulf,” he said. “We know things need to be safe and operate in a safe manner. But we don’t need to overregulate in a way that disincentivizes investment.”

Port Fourchon itself has the feel of a moon base. It is reached via an eight-mile bridge intended to keep the port operating even during flooding, an increasingly common occurrence because of damage to protective wetlands caused by drilling and dredging. Every major oil and gas company has an encampment with ships and repair warehouses. Hundreds of workers converge daily in a rush-hour scramble of muddy pickup trucks.

The port operates around the clock, 365 days a year, with hundreds of service boats and helicopters ferrying crews to and from offshore platforms and drilling rigs. Giant workboats — the equivalent of floating dump trucks — carry loads of mud, fuel, water, food and other supplies the crews require.