This summer, one of the favorite activities for tourists and residents alike on Block Island has been checking on the progress of the wind farm being built three miles offshore, gathering at Southeast Light or another nearby vantage point for the best view.

“We like to go down at the end of the day to see them,” Ken Lacoste, warden of the town council for New Shoreham, the municipality of the island, said Tuesday. “I just stand at the fence at Southeast Light with binoculars. It’s just absolutely fascinating.”

For the past three weeks the view has been changing daily, as construction crews install additional major components of the five-turbine array. As of Tuesday afternoon, work was complete on the fourth turbine, and crews were preparing to erect the three tower sections for the fifth, said Jeffrey Grybowski, chief executive officer of Deepwater Wind, the company building the 30-megawatt, $300 million project, which will produce enough power for 17,000 homes.

Once operating, it will be the first offshore wind farm in the country.

Once the final turbine is complete, which will take two days in “perfect weather,” Grybowski said, the commissioning and testing phase will begin.

“We’ll power up gradually, and by early November it will be ready” to start producing electricity, he said. “It’s not a theoretical thing anymore.”

Cmdr. Keith Hanley, of Coast Guard Sector Southeastern New England in East Providence, said no major issues have arisen with ferries, commercial and recreational fishermen and boaters, commercial shippers or other vessels during the final construction phase. He noted that the five towers are already shown on navigation charts.

“They have attracted some spectators,” he said. “But no one has interfered.”

The Coast Guard has provided escorts for the equipment vessel, as well as leading safety drills on the construction barge, which sits on a platform several feet out of the water.

Clif Payne, owner of Payne’s Dock marina, said watching the towers go up has been exciting.

“It’s a beautiful sight,” he said. “Once they start spinning, they’ll be a tourist attraction.”

Anglers, Payne said, are finding good fishing around the tower foundations, which act as artificial reefs attracting marine life. Grybowski said boaters are permitted to get as close as they like to the foundations as long as they are not touching them, but are required to stay 500 feet from the construction vessels.

Payne said he is eager for the wind farm to start operating, to replace the power now produced by diesel-fired generators by the Block Island Power Co.

“We make all of our power now out of old dinosaurs,” he said, referring to the fossil fuel plant.

Along with producing power, the Deepwater project is also giving the island a long-sought 22-mile power cable to the mainland, and a fiber optic line that will dramatically improve internet access on the island, Lacoste said. Electricity rates on the island, now three times higher than on the mainland, are expected to drop 30 to 35 percent once the wind farm begins producing power.

He noted that a fire at the power company last month, which resulted in rolling blackouts at the height of the summer tourist season, served as a timely reminder of why the wind farm is needed.

Ten years in the making, the project is attracting national media attention as interest in offshore wind power grows, Lacoste said. Commercial wind power projects are proposed in waters offshore in California, Hawaii, New York and Massachusetts.

“This is a technological feat that puts Rhode Island on the map,” he said. “When it starts operating, it’ll be like the golden spike in the Transcontinental Railroad.”

j.benson@theday.com